Networking & Internet: Types, Devices and Protocols
Networking and internet questions test whether a candidate knows how computers are joined together, what the common devices do and which protocol or service does which job. The questions are short and fact based, and the same terms repeat, so a focused revision secures this section quickly.
This deep-study note covers the basic terms, the types of networks, the devices, the important protocols and internet services, the question patterns, a solving method, the traps examiners set and a preparation plan. After reading it, a candidate should be able to identify the correct network type, device or protocol without hesitation.
Basic Terms
- Computer network: two or more computers connected to share data, resources and services.
- Node: any device connected to a network, such as a computer or a printer.
- LAN: a local area network covering a small area such as a room, a building or a campus.
- MAN: a metropolitan area network covering a city.
- WAN: a wide area network covering a large region or the whole world.
- PAN: a personal area network covering a few metres around a person.
- Topology: the layout in which nodes are connected, such as bus, star, ring, mesh or tree.
- Protocol: a set of rules that governs how data is exchanged on a network.
- IP address: a unique address that identifies a device on a network, for example 192.168.0.1.
- MAC address: the permanent physical address given to a network card.
- DNS: the domain name system that converts a domain name into an IP address.
- Bandwidth: the amount of data a connection can carry in a given time.
- Router: a device that joins different networks and forwards data between them.
- Web browser: software used to view pages on the World Wide Web.
Core Concepts and Rules
- LAN covers a small area, MAN a city and WAN a large region, and the internet is the largest WAN.
- In a star topology all nodes connect to a central hub or switch, while a bus topology uses one main cable.
- TCP/IP is the basic protocol suite of the internet, and TCP is connection oriented while UDP is connectionless.
- HTTP and HTTPS are used for the web, FTP for file transfer, and SMTP, POP3 and IMAP for e-mail.
- HTTPS is the secure version of HTTP and uses encryption; the padlock in a browser shows it.
- A hub broadcasts data to all ports, a switch sends it only to the correct port and a router joins networks.
- IPv4 uses 32-bit addresses and IPv6 uses 128-bit addresses.
- DNS changes a domain name such as axomexam.in into a numeric IP address.
- WWW is a service that runs on the internet; the internet itself is the network of networks.
- An ISP is an internet service provider that gives a user access to the internet.
Types of Networks and Topologies
A personal area network connects devices within a few metres, usually by Bluetooth, and a local area network connects computers within one building or campus. A metropolitan area network spreads over a city, and a wide area network covers states, countries or the globe, the internet being the biggest example. The layout of the connections is called the topology. In a bus topology every node shares one backbone cable, so a break stops the whole network. In a star topology every node connects to a central hub or switch, which is easy to manage and is the most common today. A ring topology joins nodes in a loop, a mesh topology connects every node to every other node and gives the highest reliability, and a tree topology joins several star networks in a hierarchy.
Devices and Protocols
A modem converts the signal of a telephone, cable or fibre line into a form a computer can use. A hub repeats data to all its ports, a switch learns which device is on which port and sends data only there, and a router connects different networks and chooses the best path between them. A gateway joins two networks that use different protocols, and a repeater and a bridge extend or divide a network. The protocol suite of the internet is TCP/IP: TCP breaks data into packets and reassembles them, and IP addresses and routes the packets. Application protocols include HTTP and HTTPS for the web, FTP for file transfer, and SMTP to send mail with POP3 or IMAP to receive it. DNS resolves names, and DHCP automatically gives an IP address to a device joining a network.
Types of Questions Asked
The most common pattern asks the full form or meaning of an abbreviation such as LAN, WAN, HTTP or DNS. The second asks which device does a given job, such as which joins two networks. The third asks which topology or network type suits a situation. The fourth asks which protocol is used for e-mail, the web or file transfer. The fifth asks the difference between two terms, such as the internet and the WWW. Direct full forms take most of the marks.
Steps to Solve a Networking Question
First, read the question and see whether it asks for an abbreviation, a device, a protocol or a topology. Second, if it asks for a full form, expand the letters one by one instead of guessing. Third, if it asks for a device, recall its one-line job, such as a router joining networks. Fourth, if it asks for a protocol, remember the service pair, such as SMTP for sending mail. Fifth, remove options that belong to a different layer or service. Finally, check the full form word by word, because one wrong word hides the correct answer.
Examination Trends
In Assam recruitment papers full forms such as LAN, WAN, WWW, HTTP, FTP and DNS, the functions of hub, switch, router and modem, types of networks and topologies, and e-mail protocols appear most often, followed by IP addressing and internet services. Questions are short and single fact based, so steady revision is enough. The same terms repeat with small changes, which makes this section quick to secure.
Common Mistakes to Avoid
- Do not confuse the internet with the World Wide Web; the web is one service on the internet.
- Do not mix a hub with a switch; a hub broadcasts while a switch sends to one port.
- Do not call FTP a web protocol; it transfers files.
- Do not confuse SMTP, which sends mail, with POP3 and IMAP, which receive it.
- Do not mix IPv4 with IPv6; IPv4 is 32-bit and IPv6 is 128-bit.
- Do not interchange HTTP and HTTPS, since HTTPS is the secure version.
How to Prepare This Topic
Make a table of the full forms of the common abbreviations, with the service each supports. Next write the devices hub, switch, router, modem and gateway with their one-line functions. Then draw the bus, star, ring, mesh and tree topologies and write one merit and one demerit of each. Finally, list the e-mail and web protocols and match each with its job.
Attempt twenty questions a day and keep a register of the full forms and device functions you got wrong, because the same items recur. Revise the difference between a hub and a switch, and between the internet and the WWW, aloud, since these are the most common traps. In the last week revise only the tables and the register, and the section will be ready.
Quick Revision Tips
- LAN small area, MAN city, WAN large region, internet the largest WAN.
- Hub broadcasts, switch forwards to one port, router joins networks.
- TCP/IP is the internet's protocol suite.
- SMTP sends mail; POP3 and IMAP receive it.
- DNS changes a domain name into an IP address.
Final Revision Note
On the last day, revise the full-form table, the device list and the topologies, then attempt a timed set of twenty questions. For every wrong answer, write the exact term that was missed. Networking questions reward clear matches between a term and its job, and a candidate who has them answers fast and gains easy marks.
Frequently Asked Questions
What is the full form of LAN and WAN?
LAN is local area network and WAN is wide area network, covering a small area and a large region respectively.
Which device joins two different networks?
A router joins two different networks and forwards data between them.
Which protocol is used to send e-mail?
SMTP, the simple mail transfer protocol, is used to send e-mail, while POP3 and IMAP are used to receive it.
What is the job of DNS?
DNS, the domain name system, converts a human-readable domain name into a numeric IP address.
What is the difference between the internet and the WWW?
The internet is the global network of networks, while the World Wide Web is one service, made of linked web pages, that runs on it.