Computer Networks
Syllabus of computer Network
● Evolution of networking: introduction to computer networks, evolution of networking (ARPANET, NSFNET, INTERNET)
● Data communication terminologies: concept of communication, components of data communication (sender, receiver, message, communication media, protocols), measuring capacity of communication media (bandwidth, data transfer rate), IP address, switching techniques (Circuit switching, Packet switching)
● Transmission media: Wired communication media (Twisted pair cable, Co-axial cable, Fiber-optic cable), Wireless media (Radio waves, Micro waves, Infrared waves
● Network devices (Modem, Ethernet card, RJ45, Repeater, Hub, Switch, Router, Gateway, WIFI card)
● Network topologies and Network types: types of networks (PAN, LAN, MAN, WAN), networking topologies (Bus, Star, Tree)
● Network protocol: HTTP, FTP, PPP, SMTP, TCP/IP, POP3, HTTPS, TELNET, VoIP
● Introduction to web services: WWW, Hyper Text Markup Language (HTML), Extensible Markup Language (XML), domain names, URL, website, web browser, web servers, web hosting
Evolution of Networking
Computer Network
What is Network?
It is a collection of Inter-connected computers and other devices that are able to communicate with each other i.e. it is a collection of hardware and software components that are connected together for effective information interchange wherein, one system/device is the sender and the other is the receiver.
Advantages of computer Network:
(i) File Sharing Networking of computer helps the user to share data files.
(ii) Hardware Sharing Users can share devices such as printers, scanners, CD-ROM drives, hard drives, etc. in a computer network.
(iii) Application Sharing Applications can be shared over the network and this allows implementation of client/server applications.
(iv) User Communication This allows users to communicate using E-mail, newsgroups, video conferencing within the network.
(v) Access to Remote Database This allows users to access remote database, e.g. airline reservation database may be accessed for ticket booking.
(vi) Central Storage of Data –
Files can be stored on a central node (the file server) that can be shared and made available to each and every user in an organization.
(vii) Improved Communication:
A computer network enables fast, reliable and secure communication between users. It saves our time and offers easy communication methods.
Ex. Sending e-mail, SMS and MMS etc.
(viii)Reduced Communication cost:
Sharing resources also reduces its communication cost. Using today’s public network we can send a large quantity of data at very low cost. Internet and Mobile network playing very important role in sending and receiving text, image, audio and video data at low cost.
ARPANET
The Advanced Research Projects Agency NETwork (ARPANET) was the world’s first operational packet switching network.
The U.S department of defense sponsored a project named ARPANET, whose goal was to connect computers at different universities and U.S defence. In 1969, the University of California at Los Angeles, the University of California and the University of Utah were connected as the beginning of the ARPANET using 50 Kbits circuits.
NSFNet
National Science Foundation Network, was started in 1980 with a view to enhance Academic and
Scientific Research. It connected its server with the ARPANET in year 1986. In the year 1990, the
NSFNet, ARPANET and other smaller networks clubbed together to form the INTERNET
(Interconnected Networks) and hence the foundation of modern INTERNET was laid down.
WWW
The World Wide Web (WWW) is a system of interlinked hypertext documents accessed via Internet. With a web browser, one can view web pages that may contain text, images, videos and other multimedia and can navigate between them via hyperlinks
Internet:
In the 1990’s, internet, which is a network of networks, came into existence. The internet has evolved from ARPANET. The computers are connected through World Wide Web that comprises a large network and shares a common communication protocol (Transmission Control Protocol-Internet Protocol, TCP/IP). It allows computers of different types to exchange information and is known as internet. Millions of domestic, business and government networks are connected with each other for the purpose of sharing files, data, email, etc. Most of the computers are not connected directly to the internet.
Instead, they are connected to smaller networks which are further connected to a backbone network through gateways.
Interspace:
Interspace is a software that allows multiple users in a client-server environment to communicate with each other by sending and receiving data of various types such as data files, video, audio and textual data in a 3-D environment. It facilitates online real-time exchange of data. Interspace is the most advanced term of communication available on the internet today.
Intranet
An intranet is a network that connects the computers and networks with in an organization that is based on Internet technology. It uses the TCP/IP protocols, server and browser software used for the Internet. With an intranet, the basic services of the Internet like E-mail, FTP, etc. are used.
Extranet:
It is the network that lies outside the limits of the IntraNet. Dell and Intel use network for business related operation.
Data communication terminologies:
COMMUNICATION
The exchange of information between two or more networked or interconnected devices is called communication. These devices must be capable of sending /receiving data over a communication medium.
Data:
It is raw facts and figures that are yet to get a defined meaning. Examples: 11, A123x@r67Y, etc.
Information:
The processed form of data that had a defined meaning is known as the information. Examples: Roll No. 11, Password: A123x@r67Y, etc.
COMPONENTS OF DATA COMMUNICATION
The five main components of data communication are as follows:
SENDER:
Sender is a device which is capable of sending data over a communication network. In data
communication Sender is also called Source.
RECEIVER:
Receiver is a device which is capable of receiving data over a communication network. In data communication Receiver is also called Destination.
MESSAGE:
message is the information being exchanged between a sender and a receiver over a communication network.
COMMUNICATION MEDIUM:
Communication medium is the path or channel through which the information is moved from the sender to the receiver. A communication medium can be either wired/guided or wireless/unguided.
PROTOCOLS:
The set of standard rules which are followed in data communication are known as Data Communication Protocols. All the communicating devices like sender receiver and other connected
devices in the network should follow these protocols.
Why Protocols are needed? The communicating devices may be in different geographical areas. The speed of these devices may be different. Also, the data transfer rates of different networks may be
different. These complexities make it necessary to have a common set of rules to ensure the secure communication of data.
Examples of some commonly used Protocols in data communication are given below:
∙Transmission Control Protocol (TCP)
∙Internet Protocol (IP)
∙File Transfer Protocol (FTP)
∙Simple Mail Transport Protocol (SMTP)
∙Hyper Text Transfer Protocol (HTTP)
MEASURING CAPACITY OF COMMUNICATION MEDIA
Capacity of a communication channel means the maximum quantity of signals that a communication channel can carry. The capacity of a communication medium is measured by its bandwidth and data
transfer rate.
Data Channel:
It is a medium to carry information or data from one point to another.
Baud:
It is the measurement of the data transfer rate in a communication channel.
Bits per Second:
It is the rate by which the data transfer is measured. It is used to measure the speed of information through high-speed phone lines or modems. It is denoted ad Bps, kbps, Mbps, Gbps, etc.
Bandwidth:
It is the difference between the highest and lowest frequencies in a channel. The high bandwidth channels are known as Broadband Channels, and the low bandwidth channels are called as the
Narrowband Channels.
Data Transfer Rate:
It is the amount of data transferred per second by a communication channel or a computing storage device. When applied to the data transmission rate, the abbreviations like K, M, G, T are added to the
data rate that denote Kilo, Mega, Giga, and Tera respectively. They work in the power of 1024.
Example 1 GB = 1024 MB, 1 TB = 1024 GB.
IP ADDRESS
IP address or Internet Protocol address is a unique numeric address assigned to every device connected to a network. It uniquely identifies every node connected to a local network or internet. An
IP address allows computers to send and receive data over the internet. They can also be used to track down a user’s physical location.
There are two versions for IP address IPV4 and IPV6. IP addresses are binary numbers but are typically expressed in decimal form (IPv4) or hexadecimal form (IPv6) to make reading and using them easily.
The commonly used IP address is IPV4. An IPv4 address consists of four numbers, each of which contains one to three digits, with a single dot (.) separating each set of digits. Each of the four numbers
can range from 0 to 255. Example IP address: 24.171.248.170
Switching Techniques
Switching techniques are used for transmitting data across networks. Different types of switching techniques are employed to provide communication between two computers. These are as follows
Circuit Switching:
Circuit switching provides end-to-end connection between two computers. It is established usually in a telephone network where one person is making a call and another is receiving a call. In a telephone system, the communication must be established between the two participants, i.e., the sender and the receiver. The circuit is established between these two participants before the transfer of data takes place.
The following actions take place during circuit switching:
- A request signal is sent by the sender to set up the connection with the receiver.
- It establishes a physical connection between the two participants.
- All intermediate nodes are identified. These nodes are also called switching nodes.
- If the destination node is available, it sends back the acknowledgement of receiving a signal. Hence, data transmission begins.
- When the data transmission is complete, the call can be terminated.
Packet switching:
In packet switching technique, the entire data is divided into small fragments called packets. Each packet is of a fixed size, usually 128 bytes or 512 bytes.
Packet switching is similar to post office operation. Each packet has a source address as well as destination address (IP address) for being transmitted, in the same way as a postman delivers a letter to a specific destination address. As there is no direct connection established between the sender and the receiver, each packet follows different routes and, therefore, the packets are delivered in a random order at the destination address. It is the TCP protocol which then arranges all received packets in a sequential order. During the transfer of packets, each packet has to pass through several intermediate nodes, so each intermediate node checks for destination IP address. If the packet matches with the node address, it is received; otherwise, it is passed on to the next node until it reaches the destination IP address.
Comparison between the various switching techniques
Criteria Circuit Switching Path Packet Switching Path
established in advance Yes No
Store and forward technique No Yes
Message follows multiple routes No Yes
Transmission media
All the computers or connecting devices in the network, must be connected to each other by a Transmission Media or channel. The selection of Media depends on the cost, data transfer speed,
bandwidth and distance.Transmission media may be classified as-
- Guided Media (Wired )
Twisted Pair Cable
Coaxial Cable
Optical Fiber - Unguided Media (Wireless)
Microwave
Radio wave
Satellite
Others (Blue tooth, Infrared and Laser etc.)
1.Twisted Pair Cables
It is most common type of media consisting insulated pairs of wires twisted around each other. Twisting helps to reduce crosstalk and Electro Magnetic Interference.
It comes in Shielded (STP) or Unshielded Twisted Pair (UTP) types. In UTP, pairs are covered by an extra insulation to further reduce the signal interference.
CAT 5 and CAT 6 are commonly used in the networking.
Advantages:
It is simple, flexible, low weight and inexpensive.
It is easy to install and maintain and requires RJ-45 Connector.
Disadvantages:
Suitable for short distance (up to 100 mt.). For long distance Repeater is required.
It supports low bandwidth and offers up to 100 Mbps speed.
2.Coaxial cable
This types of cable consists a solid insulated wire core surrounded by wire mesh or shield, each separated by some find of foil or insulator. The inner core carries the signal and mesh provides the
ground. Co-axial Cable or coax, is most common in Cable TV transmission. Generally it is used in Bus topology network.
It is two type- Thinnet (185 mt), Thicknet(500 mt)
A connector known as a vampire tap or BNC connector to connect network devices.
Advantages:
• It offers high bandwidth and better speed than other cables.
• Suitable for Broadband transmission (cable TV) and can be used in shared cable network.
Disadvantages:
• It is expensive compared to Twisted Pair cable.
• Not compatible with modern cables like UTP and STP
3. Fiber Optic
Optical Fiber consists of thin glass or glass like material and carry light. Signal are modulated and transmitted in light pulses from source using Light Emitting Diode (LED) or LASER beam.
The Fiber cable consists Core (Glass or Plastic) covered by Cladding, which reflects light back to the core. Also a Protective cover including Buffer Jacket is used for extra protection.
Two types of transmission i.e. Single mode (LESER) and Multimode (LED) is possible.
Advantages:
• It is free from EMI since no electrical signal are carried.
• Offers secure and high speed transmission up to a long distance.
Disadvantages:
• Expensive and quite fragile.
• Complicated Installation procedure and difficult to join two fiber or broken fiber.
• Not suitable for domestic purposes due to high maintenance cost.
Wireless Transmission Media
∙In wireless communication technology, information travels in the form of electromagnetic signals
through ir. ∙ E ectrom gnetic pectrum of frequency r nging from 3 KHz to 9 THz i v i b e for
wireless communication.
∙Radio Waves
1. Waves of frequency range 3 KHz – 1 GHz
2. Omni-directional, these waves can move in all directions
3. Radio waves of frequency 300KHz-30MHz can travel long distance
4. Susceptible to interference
5. Radio waves of frequency 3-300KHz can penetrate walls
6. These waves are used in AM and FM radio, television, cordless phones.
Microwaves
1. Electromagnetic waves of frequency range 1GHz – 300GHz.
2. Unidirectional, can move in only one direction.
3. Cannot penetrate solid objects such as walls, hills or mountains.
4. Needs line-of-sight propagation i.e. both communicating
antenna must be in the direction of each other.
5. Used in point-to-point communication or unicast communication such as radar and satellite.
6. Provide very large information-carrying capacity.
Infrared waves
1. Electromagnetic waves of frequency range 300GHz – 400THz.
2. Very high frequency waves.
3. Cannot penetrate solid objects such as walls.
4. Used for short-distance point-to-point communication such as mobile to mobile, mobile- to-printer, remote-control-to-TV,
Bluetooth:
Bluetooth is a short-range wireless technology commonly used for connecting devices like smartphones, laptops, and peripherals (e.g., wireless keyboards, mice, and headphones). It operates in the 2.4 GHz frequency band and supports relatively low data transfer rates compared to Wi-Fi.
Satellite Communication:
Satellite communication involves transmitting data to and from Earth through communication satellites. It is used for long-distance communication in remote areas or where traditional wired communication is not feasible.
Network devices
TYPES OF NETWORK
Repeaters:
A repeater is a network device that amplifies, restores and re-broadcasts signals for long-distance transmission.
Network Topology
In order to form a network, computers and other communicating devices (Nodes) must be interconnected in some layout.
The layout of interconnection of devices in a network is called Topology.
The major types of Topologies are-
(1) Star topology
(2) Ring topology
(3) Bus topology
(4) Tree topology
(5) Mesh
(6) fully connected
The selection of topology for a network depends on the following factors-
Cost:- It includes cable/media cost and installation cost depends on the distance between nodes.
Flexibility:- Arrangement of furniture and walls in the building may affect the selection of topology and media.
Reliability:- Fault detection during Network failure also affects the selection of topology.
NETWORK PROTOCOL:
A protocol means the rules that are applicable for a network. Protocols define standardized formats for data packets, techniques for detecting and correcting errors etc.
Domain Name System (DNS):
It translates network address (such as IP addresses) into terms understood by humans (such as domain names) and vice versa.
Domain Host Configuration Protocol (DHCP):
It automatically assigns internet addresses to computers and users.
IRC (Internet Relay Chat)
IRC is an application layer protocol that allows users to share text messages. It uses client server model where the clients install IRC client program on their system so that they can communicate with IRC chat server to transfer messages to other clients.
VoIP
VoIP stands for Voice over Internet Protocol. For transferring of voice, voice over internet protocol is used. The voice calls are first digitized, compressed and then fragmented into small packets, which are then relayed by Internet Protocol (IP) cross network.
Voice-over-IP (VoIP) implementation enables users to carry voice traffic (For example, telephone calls and faxes) over an IP network.
There are 3 main causes for the evolution of the voice-over IP market:
1. Low-cost phone calls
2. Add-on services and unified messaging
3. Merging of data/voice infrastructures
IP Address
All the computers on the Network follow the some set of rules (Protocol) for Communication to each other. One of the most common protocol is TCP/IP.
Each machine in TCP/IP network needs to have a unique 32 bit (4 Byte) address called IP address.
The IP address may be static (permanent )or dynamic (temporary) depending on the network or service provider.
IPv4 addresses are usually represented in dot-decimal notation (four numbers, each ranging from 0 to 255, separated by dots). Example- 208.77.188.166.
TCP/IP (Transmission Control Protocol/Internet Protocol)
• It is a set of standardized rules that uses a client-server model of communication in which a user or machine (a client) requests a service by a server in the network.
• The IP protocol ensures that each computer or node connected to the Internet is assigned an IP address, which is used to identify each node independently.
• TCP ensures that the message or data is broken into smaller chunks, called IP packets. Each of these packets are routed (transmitted) through the Internet, along a path from one router to the next, until it reaches the specified destination. TCP guarantees the delivery of packets on the designated IP address. It is also responsible for ordering the packets so that they are delivered in sequence.
POP3 (Post Office Protocol 3)
The POP (Post Office Protocol 3) is a simple and standard method to access mailbox and download messages to the local computers. The user can receive messages with the help of POP protocol. The advantage is that once the messages are downloaded, an internet connection is no longer needed to read the mail. A user can read all emails offline as these are saved on the computer’s hard disk.
SMTP (Simple Mail Transfer Protocol.)
SMTP is a set of communication guidelines that allow software to transmit an electronic mail over the internet is called Simple Mail Transfer Protocol.
• It is a program used for sending messages to other computer users based on e-mail addresses.
• It provides a mail exchange between users on the same or different computers, and it also supports:
• It can send a single message to one or more recipients.
• Sending message can include text, voice, video or graphics.
• It can also send the messages on networks outside the internet.
• The main purpose of SMTP is used to set up communication rules between servers.
TELNET :
Telnet is a remote login that helps a user to log on to another user’s terminal without being its original user. A user who is logging in to their own system can also get access to log on to another user system and perform various functions such as accessing files or sharing files to/from the remote system. With TELNET, a user logs in as a regular user with whatever privileges that may have been granted to the specific application and data on that computer
GSM stands for Global System for Mobile communication.
It provides its subscribers with roaming facility so that they can use their mobile phones all over the world to communicate with each other. GSM provides digital signalling as well as digital call facility and is so considered as a second generation (2G) mobile phone system. It provides consumers with better voice quality and low-cost alternatives to making calls such as short message service (SMS). It has an ability to carry 64 kbps to 120 mbps of data rates.
CDMA (Code Division Multiple Access)
CDMA stands for Code Division Multiple Access. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. It is a channel access method used by various radio communication technologies. It allows the division of transmission medium into different channels so that transmission from different stations is separated from each other. It employs spread spectrum digital technology where the data is fragmented into small chunks over a number of different frequencies available for use. Analog to digital conversion takes place where audio input is first digitized into binary elements. The CDMA system works directly on 64 kbit/sec.
HTTP – Hyper Text Transfer Protocol
• HTTP is used to transfer data across the web. HTTP specifies how to transfer hypertext (linked web documents) between two computers.
• It allows users of the World Wide Web to exchange information found on web pages.
• When accessing any web page entering http:// in front of the address tells the browser to communicate over HTTP.
• Clients (web browsers) send requests through request object of http to web servers for web pages, resources etc
HTTPS (Hyper Text Transfer Protocol secure)
The more secure and advanced version is HTTPS. It is used for secure communication over a computer network.
HTTPS provides,
• Encryption: Encrypting the exchanged data to keep it secure from eavesdroppers.
• Data integrity: Data cannot be modified or corrupted during transfer.
• Authentication: Proves that your users communicate with the intended website.
FTP- (File Transfer Protocol)
It is a standard internet protocol provided by TCP/IP used for transmitting the files from one host to another. It is mainly used for transferring the web page files from their creator to the computer that acts
as a server for other computers on the internet. It is also used for downloading the files to computer from other servers.
PPP- Point-to-Point Protocol
(PPP) is protocol that is used to connect one computer system to another. Computers use PPP to communicate over the telephone network or the Internet. A PPP connection exists when two systems
physically connect through a telephone line. You can use PPP to connect one system to another.
GPRS (General Packet Radio Services)
GPRS or General Packet Radio Services provides various features over 2G phones with respect to high speed data transfer. A user can send and receive data at the same time and thus uses the same bandwidth for both purposes. Using GPRS technology, a user can make a call and at the same time receive a message without disconnecting the call. However, GPRS usage is charged for the amount of data sent or received. GPRS can provide data rates up to 32kbps to 48kbps.
Wireless in Local Loop (WLL)
Wireless Local Loop (wireless in local loop) technology, the subscriber is connected to the nearest exchange through a radio link instead of copper wires. Wireless in local loop is cheaper and quicker than copper wire connectivity. As the
cost of copper along with the cost of digging increases over time, this method proves cheaper than using copper wires. It is used in remote areas where digging for copper wires is not possible.
ELECTRONIC MAIL (EMAIL)
Email is a method of exchanging digital messages from a sender to one or more recipients.
Some common email protocols are:
• Internet Message Access Protocol (IMAP): A protocol for receiving email messages on the internet.
• Post Office Protocol Version 3 (POP3): A protocol used by email clients to retrieve messages from remote servers.
• Simple Mail Transfer Protocol (SMTP): A protocol used for sending email messages on the internet.
• GOPHER: Another tool of the internet is Gopher, a menu-based program that enables us to browse for information without knowing where the material is located. It lets us search a list of resources and then sends the material to us
VIDEO CONFERENCING
Video conferencing is a communications technology that integrates video and audio to connect users anywhere in the world as if they were in the same room. This term usually refers to communication between three or more users who are in at least two locations, rather than one-on-one communication and it often includes multiple people at each location. Each user or group of users who is participating in a video conference typically must have a computer, a camera, a microphone, a video screen and a sound system.
Basically, this is a system that allows us to conduct meetings or trainings in different places simultaneously. So, this technology is especially popular in the field of business because it allows meetings or conferences to be held without the need for all the participants to travel to a single location, so it saves time and money.
The most popular software used for video conferencing is:
(a) Zoom
(b) Skype
INTRODUCTION TO WEB SERVICES
World Wide Web (WWW):
It is a global system of interconnected documents and resources that are accessible over the internet.
It operates on the basis of hypertext links which allows the users to navigate between different documents and multimedia content.
Hypertext:
The web is built on the concept of hypertext where documents are linked to each other through hyperlinks. These allow the users to navigate from one place to another.
URL:(Uniform Resource Locator).
A Uniform Resource Locator (URL) is the address of a unique resource on the internet. Often referred to as a “web address,” it tells your web browser where to find a specific webpage, image, file, or service, and how to access it (using protocols like HTTP or HTTPS).
Anatomy of a URL with an Example
Let’s break down the different parts of a complex URL:
Here is what each component represents:
1. Scheme (or Protocol)
Example:
https://Explanation: The scheme defines the protocol the browser should use to communicate with the server. Common schemes include
http(Hypertext Transfer Protocol),https(HTTP Secure, which encrypts data),ftp(File Transfer Protocol), andmailto(for sending emails).
2. Subdomain
Example:
wwwExplanation: A subdivision of the main domain name. It helps organize and navigate to different sections of a website (e.g.,
blog.example.com,shop.example.com). Thewwwis the most common subdomain, representing the World Wide Web.
3. Domain Name
Example:
example.comExplanation: The unique name that identifies the website’s server on the internet. It consists of the Second-Level Domain (
example) and the Top-Level Domain or TLD (.com,.org,.net,.edu).
4. Port
Example:
:443Explanation: A technical “gate” used to specify which network port on the server to connect to. Port
80is standard for HTTP, and port443is standard for HTTPS. Ports are usually hidden in URLs because browsers use the default port for the chosen scheme automatically.
5. Path
Example:
/products/item.htmlExplanation: The specific location, directory, or file structure on the web server. It points the browser to the exact folder or resource the user wants to view, mimicking how folders are organized on your computer.
6. Query String (Parameters)
Example:
?id=123&category=booksExplanation: Additional information passed to the server, starting with a question mark (
?). It consists of key-value pairs separated by ampersands (&). In this example, the query tells the server to look up itemid123 within thecategorybooks.
Web Browser:
To access and view web pages on the internet (WWW), we need to have an application named as Web Browser. There are many web browsers available on the internet like Google Chrome, Microsoft Edge, and Mozilla Firefox etc.
Web Servers:
These are the computers that host websites and web applications. These respond to requests from web browsers, and provide the requested web pages and resources back to the users.
A web server is hardware (a computer) or software that stores website files (like HTML, images, and code) and delivers them to users over the internet when requested by a browser.
Top Examples:
Nginx: Extremely fast, great for high-traffic websites and handling thousands of simultaneous connections.
Apache: Highly flexible, reliable, and powers a large portion of traditional websites and WordPress.
Microsoft IIS: Designed by Microsoft for Windows environments and
.NETapplications.Node.js: Lightweight server environment used to build custom APIs and real-time apps in JavaScript.
Weblinks:
These are the links available within the web pages that allow the users to access the pages that contain the topic related content.
HTML:
Hyper Text Markup Language (HTML) was developed with a view to structure and organize the static web pages. These are the symbols and codes that allow the used to develop web pages that can run over the internet. These define the layout, format, and linking of text, multimedia, and other elements within a web page. It uses tags for presentation of content.
XML:
Extensible Markup Language (XML) is designed to carry and store data in a structured and platform independent format. These use the user-defined custom tags to represent specific data fields and structures. These are self-descriptive and make it easier for different applications to understand and interpret data.
Client Script
A client script (or client-side script) is code that runs directly inside the user’s web browser, rather than on the web server.
It handles interactivity, animations, form validations, and dynamic UI updates instantly without requiring a full page reload from the server.
Popular Client-Side Languages & Libraries
JavaScript (JS): The core language supported by all web browsers.
React / Vue / Angular: Modern frontend frameworks used to build complex, interactive web interfaces using client-side scripts.
TypeScript: Compiles down to JavaScript for browser execution.
EXPANDED FORMS
ARPANET – Advance Research Project Agency Network
NIU – Network Interface Unit
LAN – Local Area Network
MAN – Metropolitan Area Network
WAN– Wide Area Network
ISP– Internet Service Provider
OSS– Open Source Software
ISDN– Integrated Service Digital Network
FLOSS – Free Libre Open Source Software
NIC – Network Interface Card
UTP – Unshielded Twisted Pair
STP – Shielded Twisted Pair
MODEM – Modulator Demodulator
RJ-45 – Registered Jack -45
XML – Extensible Markup Language
FTP – File Transfer Protocol
TCP – Transmission Control Protocol
SMTP – Simple Mail Transfer Protocol
POP3 – Post Office Protocol 3 (Version 3)
IMAP – Internet Message Access Protocol
IP – Internet Protocol
SLIP – Serial Line Internet Protocol
PPP – Point To Point Protocol
PDA – Personal Data Assistant
GSM – Global System For Mobile
SIM – Subscriber Identity Module
CDMA – Code Division Multiple Access
WLL – Wireless In Local Loop
WWW – World Wide Web
URL – Uniform Resource Locator
DHTML – Dynamic Hyper Text Markup Language
OSS – Open Source Software
GNU – GNU’s Not Unix
FSF – Free Software Foundation
OSI – Open Source Initiative
HTTP – Hyper Text Transfer Protocol
HTTPS – Hyper Text Transfer Protocol Secure
HTML – Hyper Text Markup Language
W3C – World Wide Web Consortium
ASP – Active Server Pages
JSP – Java Server Pages