Operating System Types

Single-user systems

A computer system that allows only one user to use the computer at a given time is known as a single-user system. The goals of such systems are maximizing user convenience and responsiveness, instead of maximizing the utilization of the CPU and peripheral devices.

Single-user systems use I/O devices such as keyboards, mice, display screens, scanners, and small printers. They can adopt technology developed for larger operating systems.

They may run different types of operating systems, including DOS, Windows, and MacOS. Linux and UNIX operating systems can also be run in single-user mode.

Batch Systems

Early computers were large machines run from a console with card readers and tape drives as input devices and line printers, tape drives, and card punches as output devices. The user did not interact directly with the system; instead, the user prepared a job, (which consisted of the program, data, and some control information about the nature of the job in the form of control cards) and submitted this to the computer operator. The job was in the form of punch cards, and at some later time, the output was generated by the system. The output consisted of the result of the program, as well as a dump of the final memory and register contents for debugging.

To speed up processing, operators batched together jobs with similar needs and ran them through the computer as a group. For example, all FORTRAN programs were compiled one after the other.

The major task of such an operating system was to transfer control automatically from one job to the next. Such systems in which the user does not get to interact with his jobs and jobs with similar needs are executed in a “batch”, one after the other, are known as batch systems. Digital Equipment Corporation’s VMS is an example of a batch operating system.

Multi-programmed Systems

Such systems organize jobs so that CPU always has one to execute. In this way, CPU utilization is increased. The operating system picks and executes from amongst the available jobs in memory. The job has to wait for some task such as an I/O operation to complete. In a non-multi-programmed system CPU would sit idle while in case of multiprogrammed system, the operating system simply switches to, and executes another job.

Time-sharing systems

These are multi-user and multi-process systems. Multi-user means system allows multiple users simultaneously. In this system, a user can run one or more processes at the same time. Examples of time-sharing systems are UNIX, Linux, Windows server editions.

Real-time systems

Real time systems are used when strict time requirements are placed on the operation of a processor or the flow of data. These are used to control a device in a dedicated application. For example, medical imaging system and scientific experiments.

Operating System Examples

There are many types of operating system. Some most popular examples of operating system are:

Unix Operating System

Unix was initially written in assembly language. Later on, it was replaced by C, and Unix, rewritten in C and was developed into a large, complex family of inter-related operating systems. The major categories include BSD, and Linux.

“UNIX” is a trademark of The Open Group which licenses it for use with any operating system that has been shown to conform to their definitions.

macOS

Mac-OS is developed by Apple Inc. and is available on all Macintosh computers. It was formerly called “Mac OS X” and later on “OS X”.  MacOS was developed in 1980s by NeXT and that company was purchased by Apple in 1997.

Linux

Linux is Unix-like operating system and was developed without any Unix code. Linux is open license model and code is available for study and modification. It has superseded Unix on many platforms. Linux is commonly used smartphones and smartwatches.

Microsoft Windows

Microsoft Windows is most popular and widely used operating system. It was designed and developed by Microsoft Corporation. The current version of operating system is Windows-10.

Microsoft Windows was first released in 1985. In 1995, Windows 95 was released which only used MS-DOS as a bootstrap.

 

Operating System Components

An operating system has various components that perform different tasks for proper execution of programs. Following are main components of the operating system.

Process Management

A process can be a program in execution that needs resources like CPU time, memory, files and I/O devices to accomplish its tasks. The operating system is responsible for

• Creating and terminating user and system processes
• Suspending and resuming processes
• Providing mechanisms for process synchronization
• Providing mechanisms for process communication
• Providing mechanisms for deadlock handling

Main Memory Management

Main memory is a large array of words or bytes. These bytes are called memory locations and range in size from hundreds of thousands to billions. Every word or byte has its own address. Main memory is a repository of quickly accessible data shared by the CPU and I/O devices. It contains the code, data, stack, and other parts of a process. The central processor reads instructions of a process from main memory during the machine cycle. The OS is responsible for the following activities in connection with memory management.

• Keeping track of free memory space
• Keeping track of which parts of memory are currently being used and by whom
• Deciding which processes are to be loaded into memory when memory space becomes available
• Deciding how much memory is to be allocated to a process
• Allocating and deallocating memory space as needed
• Ensuring that a process is not overwritten on top of another

Secondary Storage Management

The programs to be executed, along with the data they access, must be in the main memory or primary storage during their execution. Since main memory is too small to accommodate all data and programs, and because the data it holds are lost when the power is lost, the computer system must provide secondary storage to backup main memory. Most programs are stored on a disk until loaded into the memory and then use disk as both the source and destination of their processing. Like all other resources in a computer system, proper management of disk storage is important.
The operating system is responsible for the following activities in connection with disk management:

• Free-space management
• Storage allocation and deallocation
• Disk scheduling

Input/Output Management

The input and output subsystem consists of:

• A memory management component that includes buffering, caching and spooling
• A general device-driver interface
• Drivers for specific hardware devices

File Management

Computers can store information on several types of physical media, e.g. magnetic tape, magnetic disk and an optical disk. The operating system maps files onto physical media and accesses these media through storage devices. Operating system is responsible for the following activities pertaining to file management:

• Creating and deleting files
• Creating and deleting directories
• Supporting primitives (operations) for manipulating files and directories
• Mapping files onto the secondary storage
• Backing up files on stable (nonvolatile) storage media

Protection System

If a computer system has multiple users and allows concurrent execution of multiple processes then the various processes must be protected from each other’s activities. Protection is any mechanism for controlling the access of programs, processes or users to the resources defined by a computer system.

Networking

A distributed system is a collection of processors that do not share memory, peripheral devices or a clock. Instead, each processor has it own local memory and clock, and the processors communicate with each other through various communication lines, such as high- speed buses or networks.

The processors in a communication system are connected through a communication network. The communication network design must consider message routing and connection strategies and the problems of contention and security.

A distributed system collects physically separate, possibly heterogeneous, systems into a single coherent system, providing the user with access to the various resources that the system maintains.

Command Line Interpreter

One of the most important system programs for an operating system is the command interpreter, which is the interface between the user and operating system. Its purpose is to read user commands and try to execute them. Some operating systems include the command interpreter in the kernel. Other operating systems (for example UNIX, Linux, and DOS) treat it as a special program that runs when a job is initiated or when a user first logs on (on time-sharing systems). Examples of shells for UNIX and Linux are Bourne shell (sh), C shell (csh), Bourne Again shell (bash), TC shell (tcsh), and Korn shell (ksh). You can use any of these shells by running the corresponding command, listed in parentheses for each shell.

 

 

Operating System (OS) Overview

Operating System is an interface between the user and the hardware and enables the interaction of a computer’s hardware and software.

Also, an operating system is a software which performs all the basic tasks like file management, memory management, storage management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

Types of Operating System (OS) 

All different operating system types are listed below –

• Windows
• iOS
• MAC OS
• Ubuntu
• Novell Netware
• Unix
• Linux

Mobile Operating System

These are some of Mobile Operating System –

• iOS
• Symbian
• Blackberry
• Windows
• Android OS
• Bada

Operating System Functions 

All  Operating system functions are shared below –

1. DEVICE MANAGEMENT –

Operating System manages device communication via their respective drivers.

It does the following activities for device management −

• Keeps tracks of all devices. I/O controller is responsible for this task
• Decides which process gets the device when and for how much time.
• Allocates the device in an efficient way.
• De-allocates devices.

2. FILE MANAGEMENT –

The operating system allocates and de-allocates resources. It regulates which process gets the file and for what duration. Also, it keeps track of information, location, uses, status etc.

The collective facilities are often known as a file system. OS also performs tasks like creating directories and files, copying/moving them and renaming/deleting files.

3. MEMORY MANAGEMENT –

Memory management refers to the management of primary or main memory. Main memory provides fast storage which can be accessed directly by CPU.

When the program is executed and finished, the memory area is freed which can be used for other programs. Computer memory is arranged such that fastest registers come 1st followed by the CPU cache, random access memory, and then disk storage.

The operating system’s memory manager coordinates the use of various types of memory, which is to be allocated or de-allocated and how to move data between them 

4. PROCESS MANAGEMENT –

Every program running on a computer is a process whether it is in the background or in frontend. The operating system is responsible for making multiple tasks to run at the same time (multitasking).

Operating system finds the status of processor and processes, chooses job and its processor allocates processor to process and de-allocates process when it’s executed.

5. MASTERMIND –

Mastermind is one term we can rightfully use for Operating system. Reason – Operating system performs a multitude of functions which only can be performed by super-intelligent mind hence the term “Mastermind”.

• OS provides Booting without an Operating System
• Provides Facility to increase the Logical Memory of the Computer System by using the Physical Memory of the Computer System.
• OS controls the Errors that have been Occurred into the Program
• Provides Recovery of the System when the System gets Damaged.
• Operating System breaks the large program into the Smaller Programs those are also called as the threads. And execute those threads one by one

6. STORAGE MANAGEMENT –

Operating System controls all Storage Operations. Some of these include – how to store data or files into the computers and how users will access the files. The operating system is Responsible for Storing and Accessing the Files. Creation of Files, Creation of Directories and Reading and Writing the data of Files and Directories and also Copy the contents of the Files and the Directories from One Place to Another Place.

 

Software Development Life Cycle

The Software Development Life Cycle (SDLC) refers to a methodology with clearly defined processes for creating high-quality software. in detail, the SDLC methodology focuses on the following phases of software development:

• Requirement analysis

• Planning

• Software design such as architectural design

• Software development

• Testing

• Deployment

This article will explain how SDLC works, dive deeper in each of the phases, and provide you with examples to get a better understanding of each phase.

What is the software development life cycle?

SDLC or the Software Development Life Cycle is a process that produces software with the highest quality and lowest cost in the shortest time possible. SDLC provides a well-structured flow of phases that help an organization to quickly produce high-quality software which is well-tested and ready for production use.

The SDLC involves six phases as explained in the introduction. Popular SDLC models include the waterfall model,spiral model, and Agile model.

How the SDLC Works

SDLC works by lowering the cost of software development while simultaneously improving quality and shortening production time. SDLC achieves these apparently divergent goals by following a plan that removes the typical pitfalls of software development projects. That plan starts by evaluating existing systems for deficiencies.

Next, it defines the requirements of the new system. It then creates the software through the stages of analysis, planning, design, development, testing, and deployment. By anticipating costly mistakes like failing to ask the end-user or client for feedback, SLDC can eliminate redundant rework and after-the-fact fixes.

It’s also important to know that there is a strong focus on the testing phase. As the SDLC is a repetitive methodology, you have to ensure code quality at every cycle. Many organizations tend to spend few efforts on testing while a stronger focus on testing can save them a lot of rework, time, and money. Be smart and write the right types of tests.

Stages and Best Practices

Following the best practices and/or stages of SDLC ensures the process works in a smooth, efficient, and productive way.

1. Identify the Current Problems 

“What are the current problems?” This stage of the SDLC means getting input from all stakeholders, including customers, salespeople, industry experts, and programmers. Learn the strengths and weaknesses of the current system with improvement as the goal.

2. Plan

“What do we want?” In this stage of the SDLC, the team determines the cost and resources required for implementing the analyzed requirements. It also details the risks involved and provides sub-plans for softening those risks.

In other words, the team should determine the feasibility of the project and how they can implement the project successfully with the lowest risk in mind.

3. Design

“How will we get what we want?” This phase of the SDLC starts by turning the software specifications into a design plan called the Design Specification. All stakeholders then review this plan and offer feedback and suggestions. It’s crucial to have a plan for collecting and incorporating stakeholder input into this document. Failure at this stage will almost certainly result in cost overruns at best and the total collapse of the project at worst.

4. Build

“Let’s create what we want.”

At this stage, the actual development starts. It’s important that every developer sticks to the agreed blueprint. Also, make sure you have proper guidelines in place about the code style and practices.

For example, define a nomenclature for files or define a variable naming style such as camelCase. This will help your team to produce organized and consistent code that is easier to understand but also to test during the next phase.

5. Code Test

“Did we get what we want?” In this stage, we test for defects and deficiencies. We fix those issues until the product meets the original specifications.

In short, we want to verify if the code meets the defined requirements.

6. Software Deployment

“Let’s start using what we got.”

At this stage, the goal is to deploy the software to the production environment so users can start using the product. However, many organizations choose to move the product through different deployment environments such as a testing or staging environment.

This allows any stakeholders to safely play with the product before releasing it to the market. Besides, this allows any final mistakes to be caught before releasing the product.

The most common SDLC examples or SDLC models are listed below.

Waterfall Model

This SDLC model is the oldest and most straightforward. With this methodology, we finish one phase and then start the next. Each phase has its own mini-plan and each phase “waterfalls” into the next. The biggest drawback of this model is that small details left incomplete can hold up the entire process.

Agile Model

The Agile SDLC model separates the product into cycles and delivers a working product very quickly. This methodology produces a succession of releases. Testing of each release feeds back info that’s incorporated into the next version. According to Robert Half, the drawback of this model is that the heavy emphasis on customer interaction can lead the project in the wrong direction in some cases.

Iterative Model

This SDLC model emphasizes repetition. Developers create a version very quickly and for relatively little cost, then test and improve it through rapid and successive versions. One big disadvantage here is that it can eat up resources fast if left unchecked.

V-Shaped Model

An extension of the waterfall model, this SDLC methodology tests at each stage of development. As with waterfall, this process can run into roadblocks.

Big Bang Model

This high-risk SDLC model throws most of its resources at development and works best for small projects. It lacks the thorough requirements definition stage of the other methods.

Spiral Model

The most flexible of the SDLC models, the spiral model is similar to the iterative model in its emphasis on repetition. The spiral model goes through the planning, design, build and test phases over and over, with gradual improvements at each pass.

Benefits of the SDLC

SDLC done right can allow the highest level of management control and documentation. Developers understand what they should build and why. All parties agree on the goal upfront and see a clear plan for arriving at that goal. Everyone understands the costs and resources required.

Several pitfalls can turn an SDLC implementation into more of a roadblock to development than a tool that helps us. Failure to take into account the needs of customers and all users and stakeholders can result in a poor understanding of the system requirements at the outset. The benefits of SDLC only exist if the plan is followed faithfully.

 

 

Computer Careers

It’s safe to say that now is a great time to pursue a career in technology. In fact, the Bureau of Labor Statistics (BLS) projects employment of professionals in computer and information technology careers to increase much faster than average.Let us introduce you to some of the many computer jobs worth considering.

1. Big data engineer

Big Data Engineers spend their work days communicating with business users and data scientists with the goal of translating business objectives into workable data-processing workflows. These positions require a robust knowledge of statistics, experience with programming and the ability to design and implement working solutions for common big data challenges.

2. Applications architect

Digital pros who land a position like applications architect are required to maintain a high level of technical expertise while also excelling in areas like planning, coordination, communication and teamwork. These professionals are tasked with designing major aspects of the architecture of an application, providing technical leadership to the development team, performing design and code reviews, ensuring enterprise-wide application standards are met and more.

3. Web developer

A web developer is the person responsible for the building and maintenance of a website. Because a website is often an organization’s primary public-facing property, it’s important for web developers to understand business needs and how to build sites that accommodate them. This position requires an in-depth knowledge of internet protocols and development languages like PHP, JavaScript, HTML5 and CSS as well.

4. Database administrator

Put simply, database administrators use specialized software to securely store and organize data, ensuring that data is both available to users and secure from unauthorized access. Additional duties include identifying user needs to create and administer databases, testing and making modifications to database structure as needed and merging old databases into new ones. Because many databases contain personal and financial information, database administrators make security a top priority.

5. Computer hardware engineer

Computer Hardware Engineers are tasked with designing, developing and supervising the production of computer hardware like keyboards, modems, printers, computer systems, chips and circuit boards. Their duties are similar to those of electronics engineers, although they focus exclusively on computer technology, with tasks like designing blueprints of new equipment, making models of new hardware designs, upgrading current computer equipment and supervising the manufacturing of new hardware.

6. Computer software engineer

Conversely, computer software engineers focus their work on designing and developing software used to control computers by utilizing the principles of computer science and mathematical analysis. You’ll typically see this work materialize through the design and development of computer games, word processors, operating systems and compilers.

7. Data security analyst

Data Security Analysts use their thorough understanding of computer and network security, including aspects like firewall administration, encryption technologies and network protocols, to perform security audits and risk assessments on behalf of their organizations, make recommendations for enhancing system security, research attempted breaches of data security, rectify security weaknesses and formulate security policies and procedures. They’re also expected to stay up-to-date with industry security trends and relevant government regulations.

8. Information systems security manager

Quality information system security managers provide leadership, guidance and training to information systems security personnel. This requires a strong technical background in tandem with excellent interpersonal and management skills. Typical duties include reviewing, implementing, updating and documenting information security policies and procedures within an organization, in addition to ensuring that legal and contractual security and privacy mandates are adhered to.

9. Health information technology careers

While jobs in technology continue to rise in prevalence, so too do jobs in the healthcare field.Health Information technology (HIT) is an excellent way to blend the two, launching your career in the midst of rapid growth. The HIT field is a specialized subset of information technology professionals who work for medical facilities and other healthcare organizations to increase the efficiency and quality of clinical care through technology. You can expect to encounter tech positions in healthcare environments that center on elements like electronic billing and coding systems, electronic medical records and networks for digital imaging.

10. Statistician

Quality statisticians are needed in a litany of different industries, including economics, government, business, biology, engineering, politics, public health, medicine, psychology, marketing, education and even sports. They collect, analyze and present data using their knowledge of statistics to conduct surveys, opinion polls and more. Statisticians use their technical skills to determine how to best collect information, what groups to test, what questions to ask and how to interpret and publish their findings.

11. Mathematician

Mathematicians use mathematical theory, algorithms and computational methods to answer questions relating to everything from economics, business and engineering to physics and other sciences. They are often tasked with both utilizing existing mathematical theories and developing new ones to connect previously unknown relationships between mathematical concepts. Our digital landscape’s influx of technical capabilities has catapulted mathematicians’ abilities to develop data-driven solutions for real-world problems.

12. Business intelligence analyst

Business intelligence analyst are responsible for designing and developing data analysis and reporting solutions, communicating analysis results while making recommendations to senior management teams and developing data cleansing regulations for their organizations. In order to land this computer career, you’ll need to have a strong background in database technology, analytical reporting and languages like SQL and Python, while also demonstrating excellent written and oral communication skills.

13. Computer and information research scientist

These high skilled professionals spend their work days inventing and designing new approaches to computing technology while also discovering innovative uses for technologies that already exist. Computer and information research scientists can work in business, science, medicine and other fields to study and solve complex problems, creating and improving computer software and hardware.

14. Network architect

Network Architect use their backgrounds in networking technology to assess business and application requirements for phone, data and internet systems for an organization. This includes planning, designing and upgrading network installation projects, troubleshooting network architecture, making recommendations for system enhancements and maintaining backup, version-control and defense systems. Network architects help business leaders make informed decisions on network investments that fit their short and long-term needs.

15. Systems engineer

This experienced tech position requires the ability to communicate complex information to technical and nontechnical users, relying on an in-depth knowledge of the technology in use, as well as advanced analytical, troubleshooting and design skills. Systems Engineers are charged with developing, maintaining and supporting technical infrastructure, hardware and system software components, while also providing user support across multiple infrastructure platforms.

16. Computer support specialist

The important work of computer supprort specialists is pretty accurately explained by the title itself. They provide help and advice to computer users and organizations by offering technical assistance directly to computer users. This includes regular testing, troubleshooting and overall maintenance of existing network systems.

17. Mobile application developer

Mobile Application Developers specialize in coding, testing, debugging and monitoring mobile apps. They use their strong analytical and programming skills to contribute to the development of ongoing projects, recommending changes and enhancements to software applications as needed. Most mobile application developer positions will require previous experience building mobile applications across a number of different platforms, in addition to knowledge of common mobile development languages.

Common Computer, IT, and Technology Abbreviations

There are literally thousands of computer abbreviations out there. Many are concerned with the technical aspects of the computer, while others deal with personal communication. Following are some more common ones that you may have heard but do not know exactly what they mean.

Common Computer Abbreviations

Operating Systems and Data Storage

Two of the most basic components of any computer system are its operating system and data storage. Many acronyms reflect these basic requirements.

• AFA - This acronym stands for All Flash Array, a grouping of flash memory devices that helps boost performance.

• BIOS - This is the Basic Input Output System, which controls the computer, telling it what operations to perform. These instructions are on a chip that connects to the motherboard.

• BYTE - A byte is a storage unit for data. KB is a kilobyte (1024 bytes); MB is a megabyte (1 million bytes); and GB is a gigabyte (1000 megabytes).

• CPU - This stands for the Central Processing Unit of the computer. This is like the computer's brain.

• HDD - This is an acronym for Hard Disk Drive, the traditional spinning drives that store information.

• LCD - This stands for Liquid Crystal Display, a type of computer screen.

• MAC - This is an abbreviation for Macintosh, which is a type of personal computer made by the Apple Computer company.

• OS - This is the Operating System of the computer. It is the main program that runs on a computer and begins automatically when the computer is turned on.

• PC - This is the abbreviation for personal computer. It originally referred to computers that were IBM compatible.

• PDF - This represents the Portable Document Format, which displays files in a format that is ready for the web.

• RAID - A type of storage that can be configured in different ways to provide a redundant copy of files, RAID stands for Redundant Array of Independent Disks.

• RAM - This stands for Random Access Memory, which is the space inside the computer that can be accessed at one time. If you increase the amount of RAM, then you will increase the computer's speed. This is because more of a particular program is able to be loaded at one time.

• RDMA - This stands for Remote Direct Memory Access.

• ROM - This is Read Only Memory, which is the instruction for the computer and cannot be altered.

• SATA - This stands for Serial Advanced Technology Attachment, a type of hard drive technology.

• SDS - This stands for Software-Defined Storage, a type of data storage that separates the data from its associated software.

• SSD - This acronym stands for Solid State Drive, a more modern type of hard drive that has no moving parts.

• VGA - The Video Graphics Array is a system for displaying graphics. It was developed by IBM.

Internet, Networking, and Connectivity

Moving beyond the physical computer right in front of you, acronyms related to networking and getting online are equally numerous and diverse.

• DNS - This stands for Domain Name Server; this can help recognize an IP address used by a domain name.

• FTP - This is a service called File Transport Protocol, which moves a file between computers using the Internet.

• HTML - HyperText Markup Language formats information so it can be transported on the Internet.

• HTTP - Hypertext Transfer Protocol is a set of instructions for the software that controls the movement of files on the Internet.

• IP - This stands for Internet Protocol which is the set of rules that govern the systems connected to the Internet. IP Address is a digital code specific to each computer that is hooked up to the Internet.

• ISP - The Internet Service Provider is the company which provides Internet service so you can connect your computer to the Internet.

• LAN - This stands for Local Area Network, which consists of the servers that your computer connects to in your local area.

• PPP - Point-to-Point Protocol is the set of rules that allow your computer to use the Internet protocols using a phone line and modem.

• SEO - This is an acronym for Search Engine Optimization.

• URL - This is the Uniform Resource Locator, which is a path to a certain file on the World Wide Web. It is what you may also call the web address.

• USB - The Universal Serial Bus is used for communications between certain devices. It can connect keyboards, cameras, printers, mice, flash drives, and other devices. Its use has expanded from personal computers to smartphones and video games, and is used as a power cord to connect devices to a wall outlet to charge them.

• VR - Virtual Reality simulates a three-dimensional scene on the computer and has the capability of interaction. This is widely used in gaming.

• VRML - Virtual Reality Mark-up Language allows the display of 3D images.

• WYSIWYG - This initialism stands for What You See Is What You Get. It is pronounced "wizziwig" and basically means that the printer will print what you see on your monitor. It also describes web design programs where what you see in the program is how the website will appear to the end user.

Common Cloud Computing Abbreviations

Cloud computing has its own set of acronyms and IT abbreviations that can easily confuse people. These are a few of the common ones:

• BYOC - This stands for Bring Your Own Cloud, often referring to cloud-based file-sharing software.

• IaaS - This acronym stands for Infrastructure as a Service. It means a service that provides data storage and servers remotely for clients.

• SaaS - This stands for Software as a Service and refers to on-demand software stored in the cloud.

• VDI - This abbreviation stands for Virtual Desktop Infrastructure and refers to a virtual desktop that can be accessed by several users.

• VPN - This stands for Virtual Private Network and is used to represent a secure connection between a network and a user.

Common AI Abbreviations

AI, which stands for Artificial Intelligence, is becoming more common all the time. From your phone to the way you interact with your television, people encounter AI every day. These are some of the common acronyms and abbreviations that go with it:

• AI - Short for artificial intelligence, AI refers to the development of computer systems to perform tasks like speech recognition and object assessment.

• ASR - This stands for Automatic Speech Recognition and refers to computers’ ability to understand your speech.

• DL - This acronym stands for Deep Learning, referring to complicated tasks that require many layers of integration in a machine’s neural network.

• FKP - This stands for Facial Key Points, the places software looks to recognize faces.

• ML - ML stands for Machine Learning, the ability of a machine to learn and integrate new information.

Common Email and Chat Abbreviations

Email and web communication require certain abbreviations of their own, including symbols that stand in for facial expressions.

Email Abbreviations

You’ll also see some of these email abbreviations used in texting and online messaging.

• AFK - Away From Keyboard

• BC - Blind Copy

• CIAO - Check It All Out

• GAL - Get A Life

• GMTA - Great Minds Think Alike

• J4F - Just For Fun

• KISS - Keep it Simple, Stupid

• LOL - Laughing Out Loud

• Re: - Regarding

• TIC - Tongue In Cheek

• TL;DR - Too Long, Didn't Read

Emoticons

Instead of abbreviating a word or phrase, emoticons attempt to resemble the visual expressions on a human face.

• :) or :-) - Smiley face

• :.( - Crying face

• :-> - Grinning

• :-| - Indifferent or bored

• :-( - Sad face

• ;-) - Winking

• :-O - Yelling

Introduction

A basic understanding of networking is important for anyone managing a server. Not only is it essential for getting your services online and running smoothly, it also gives you the insight to diagnose problems.

This document will provide a basic overview of some common networking concepts. Here we will discuss basic terminologies.

This guide is operating system agnostic, but should be very helpful when implementing features and services that utilize networking on your server.

Networking Glossary

Before we begin discussing networking with any depth, we must define some common terms that you will see throughout this guide, and in other guides and documentation regarding networking.

These terms will be expanded upon in the appropriate sections that follow:

• Connection: In networking, a connection refers to pieces of related information that are transfered through a network. This generally infers that a connection is built before the data transfer (by following the procedures laid out in a protocol) and then is deconstructed at the at the end of the data transfer.

• Packet: A packet is, generally speaking, the most basic unit that is transfered over a network. When communicating over a network, packets are the envelopes that carry your data (in pieces) from one end point to the other.

Packets have a header portion that contains information about the packet including the source and destination, timestamps, network hops, etc. The main portion of a packet contains the actual data being transfered. It is sometimes called the body or the payload.

• Network Interface: A network interface can refer to any kind of software interface to networking hardware. For instance, if you have two network cards in your computer, you can control and configure each network interface associated with them individually.

A network interface may be associated with a physical device, or it may be a representation of a virtual interface. The “loopback” device, which is a virtual interface to the local machine, is an example of this.

• LAN: LAN stands for “local area network”. It refers to a network or a portion of a network that is not publicly accessible to the greater internet. A home or office network is an example of a LAN.

• WAN: WAN stands for “wide area network”. It means a network that is much more extensive than a LAN. While WAN is the relevant term to use to describe large, dispersed networks in general, it is usually meant to mean the internet, as a whole.

If an interface is said to be connected to the WAN, it is generally assumed that it is reachable through the internet.

• Protocol: A protocol is a set of rules and standards that basically define a language that devices can use to communicate. There are a great number of protocols in use extensively in networking, and they are often implemented in different layers.

Some low level protocols are TCP, UDP, IP, and ICMP. Some familiar examples of application layer protocols, built on these lower protocols, are HTTP (for accessing web content), SSH, TLS/SSL, and FTP.

• Port: A port is an address on a single machine that can be tied to a specific piece of software. It is not a physical interface or location, but it allows your server to be able to communicate using more than one application.

• Firewall: A firewall is a program that decides whether traffic coming into a server or going out should be allowed. A firewall usually works by creating rules for which type of traffic is acceptable on which ports. Generally, firewalls block ports that are not used by a specific application on a server.

• NAT: NAT stands for network address translation. It is a way to translate requests that are incoming into a routing server to the relevant devices or servers that it knows about in the LAN. This is usually implemented in physical LANs as a way to route requests through one IP address to the necessary backend servers.

• VPN: VPN stands for virtual private network. It is a means of connecting separate LANs through the internet, while maintaining privacy. This is used as a means of connecting remote systems as if they were on a local network, often for security reasons

Electronic Commerce

E-Commerce or Electronic Commerce means buying and selling of goods, products, or services over the internet. E-commerce is also known as electronic commerce or internet commerce. These services provided online over the internet network. Transaction of money, funds, and data are also considered as E-commerce. These business transactions can be done in four ways: Business to Business (B2B), Business to Customer (B2C), Customer to Customer (C2C), Customer to Business (C2B). The standard definition of E-commerce is a commercila transaction which is happened over the internet. Online stores like Amazon, Flipkart, Shopify, Myntra, Ebay, Quikr, Olx are examples of E-commerce websites. By 2020, global retail e-commerce can reach up to $27 Trillion. Let us learn in detail about what is the advantages and disadvantages of E-commerce and its types.

E-Commerce or Electronic Commerce

E-commerce is a popular term for electronic commerce or even internet commerce. The name is self-explanatory, it is the meeting of buyers and sellers on the internet. This involves the transaction of goods and services, the transfer of funds and the exchange of data.

Types of E-Commerce Models

Electronic commerce can be classified into four main categories. The basis for this simple classification is the parties that are involved in the transactions. So the four basic electronic commerce models are as follows,

1. Business to Business

This is Business to Business transactions. Here the companies are doing business with each other. The final consumer is not involved. So the online transactions only involve the manufacturers,whole salers and retailers etc.

2. Business to Consumer

Business to Consumer. Here the company will sell their goods and/or services directly to the consumer. The consumer can browse their websites and look at products, pictures, read reviews. Then they place their order and the company ships the goods directly to them. Popular examples are Amazon, Flipkart, Jabong etc.

3. Consumer to Consumer

Consumer to consumer, where the consumers are in direct contact with each other. No company is involved. It helps people sell their personal goods and assets directly to an interested party. Usually, goods traded are cars, bikes, electronics etc. OLX, Quikr etc follow this model.

4. Consumer to Business

This is the reverse of B2C, it is a consumer to business. So the consumer provides a good or some service to the company. Say for example an IT freelancer who demos and sells his software to a company. This would be a C2B transaction.

Advantages of E-Commerce

• E-commerce provides the sellers with a global reach. They remove the barrier of place (geography). Now sellers and buyers can meet in the virtual world, without the hindrance of location.

• Electronic commerce will substantially lower the transaction cost. It eliminates many fixed costs of maintaining brick and mortar shops. This allows the companies to enjoy a much higher margin of profit.

• It provides quick delivery of goods with very little effort on part of the customer. Customer complaints are also addressed quickly. It also saves time, energy and effort for both the consumers and the company.

• One other great advantage is the convenience it offers. A customer can shop 24×7. The website is functional at all times, it does not have working hours like a shop.

• Electronic commerce also allows the customer and the business to be in touch directly, without any intermediaries. This allows for quick communication and transactions. It also gives a valuable personal touch.

Disadvantages of E-Commerce

• The start-up costs of the e-commerce portal are very high. The setup of the hardware and the software, the training cost of employees, the constant maintenance and upkeep are all quite expensive.

• Although it may seem like a sure thing, the e-commerce industry has a high risk of failure. Many companies riding the dot-com wave of the 2000s have failed miserably. The high risk of failure remains even today.

• At times, e-commerce can feel impersonal. So it lacks the warmth of an interpersonal relationship which is important for many brands and products. This lack of a personal touch can be a disadvantage for many types of services and products like interior designing or the jewelry business.

• Security is another area of concern. Only recently, we have witnessed many security breaches where the information of the customers was stolen. Credit card theft, identity theft etc. remain big concerns with the customers.

• Then there are also fulfillment problems. Even after the order is placed there can be problems with shipping, delivery, mix-ups etc. This leaves the customers unhappy and dissatisfied.