A computer network is a group of devices connected together. The main purpose is to share information and resources. Think of your home Wi-Fi network. Your phone, laptop, and smart TV can all connect to the internet and sometimes to each other. That's a network in action.

Without networks, sharing a file with a friend would mean saving it to a flash drive and physically handing it to them. With a network, you can send it in seconds. This ability to share resources, like an internet connection or a printer, and information, like files and messages, is what makes networks so powerful.

Every network, no matter how big or small, is built from the same fundamental parts. Let's look at the different scales networks can operate on.

Networks are categorized based on the geographical area they cover. The three main types are LAN, WAN, and MAN.

A Wide Area Network (WAN) covers a large geographical area, like a country or even the entire planet. WANs are used to connect different LANs together. The internet is the largest WAN in the world, connecting billions of devices globally.

A Metropolitan Area Network (MAN) sits between a LAN and a WAN. It typically covers a city or a large campus. A university might use a MAN to connect the networks in its various buildings across town.

All networks rely on three basic components to function: nodes, links, and protocols.

Links are the transmission media that connect the nodes. They are the pathways for data. Links can be physical, like copper Ethernet cables or fiber optic cables, or they can be wireless, using radio waves like Wi-Fi and Bluetooth.

Think of a protocol as a shared language. If two people want to communicate, they must speak the same language. Similarly, for two devices on a network to exchange information, they must use the same protocols. These rules govern everything from how a connection is started to how errors are handled, ensuring communication is reliable and orderly.