Introduction to Computer Networks
What a computer network is, what it connects, what moves across it, and where we use networks every day.
2 min read
Class 12 · Chapter 1
This chapter explains how computers, phones and printers connect and share data. You will learn the main types of networks, the devices that join them, how they can be arranged, the seven layers of the OSI model, the protocols that carry web pages and names, and how IP addresses work. Then you will set up and secure a home network, test it with simple commands, and see how speed, load balancing, security and backups keep a network safe and fast.
What a computer network is, what it connects, what moves across it, and where we use networks every day.
2 min read
How a network is designed, what it is made of, and how data travels across it in small packets.
3 min read
LAN, WAN and the Internet: how networks are grouped by size and coverage area, and how they differ.
3 min read
The five devices that build a network: NIC, switch, router, modem and wireless access point, and the job of each one.
3 min read
Bus, star, ring, mesh and tree: five ways to arrange a network, with the advantages and disadvantages of each.
4 min read
Why networks split communication into layers, and what each of the seven OSI layers does.
3 min read
The rules computers follow to talk: TCP/IP, HTTP and HTTPS, FTP, and DNS, which turns website names into IP addresses.
3 min read
How every device gets an address, how IPv4 and IPv6 addresses look, how a network is split into subnets, and what NAT does.
3 min read
What a home network is, the parts it needs, and how wired and wireless connections compare.
2 min read
Why Wi-Fi needs security, how to reach your router's settings, what encryption and the default gateway do, and why guest networks help.
3 min read
Commands that check a network: ping tests if a device answers, ipconfig and ifconfig show your settings, Telnet, PuTTY and SSH give remote access.
3 min read
How well a network works: bandwidth (how much data it carries), latency (how long data takes) and the common causes of delay.
2 min read
How big networks share work among many servers so that no single device is overloaded, and the three basic methods they use.
2 min read
How firewalls, encryption and access control keep a network safe, and the common threats they protect against.
3 min read
Why we keep copies of important data, the three types of backup, and four ways to get lost data back.
2 min read
Why making a system safer can make it harder to use, and why good systems balance both.
2 min read
What a computer network is, what it connects, what moves across it, and where we use networks every day.
2 min read
How a network is designed, what it is made of, and how data travels across it in small packets.
3 min read
LAN, WAN and the Internet: how networks are grouped by size and coverage area, and how they differ.
3 min read
The five devices that build a network: NIC, switch, router, modem and wireless access point, and the job of each one.
3 min read
Bus, star, ring, mesh and tree: five ways to arrange a network, with the advantages and disadvantages of each.
4 min read
Why networks split communication into layers, and what each of the seven OSI layers does.
3 min read
The rules computers follow to talk: TCP/IP, HTTP and HTTPS, FTP, and DNS, which turns website names into IP addresses.
3 min read
How every device gets an address, how IPv4 and IPv6 addresses look, how a network is split into subnets, and what NAT does.
3 min read
What a home network is, the parts it needs, and how wired and wireless connections compare.
2 min read
Why Wi-Fi needs security, how to reach your router's settings, what encryption and the default gateway do, and why guest networks help.
3 min read
Commands that check a network: ping tests if a device answers, ipconfig and ifconfig show your settings, Telnet, PuTTY and SSH give remote access.
3 min read
How well a network works: bandwidth (how much data it carries), latency (how long data takes) and the common causes of delay.
2 min read
How big networks share work among many servers so that no single device is overloaded, and the three basic methods they use.
2 min read
How firewalls, encryption and access control keep a network safe, and the common threats they protect against.
3 min read
Why we keep copies of important data, the three types of backup, and four ways to get lost data back.
2 min read
Why making a system safer can make it harder to use, and why good systems balance both.
2 min read