Introduction to LAN

A LAN (Local Area Network) is a local network.
It is used to connect devices that are physically close to each other.

A LAN usually exists in the same location, such as a home, an office, a room, or a single floor of a building.

Example of a Local Area Network

Inside a LAN, devices communicate locally without needing to reach other networks.
As long as devices belong to the same LAN, they can communicate with each other through the switch.

Figure 1 – Devices inside the same Local Area Network (LAN)

Here, you can see an example with three PCs connected to the same network.
All these devices are part of the same LAN and can communicate with each other.

Inside a Local Area Network, devices rely on a switch to communicate.
When multiple devices are connected in a LAN, the switch is used to receive data from one device and forward it to the correct destination.

When a device sends data, the traffic goes to the switch first.
The switch then forwards the data to another device inside the same LAN.

Figure 2 – Devices exchanging data locally through a switch inside the LAN

When a device sends data, the traffic goes to the switch first.
The switch then forwards the data to another device inside the same LAN.

As long as devices belong to the same LAN, all communication stays local and does not require a router.

Now that you understand how devices communicate inside a LAN, let’s look at where this communication happens in the OSI model.