3. Hub

Hubs are a piece of hardware used to connect computers on the same network together. Every device gets plugged into the hub via cables. The hub has a socket, or 'port' available for each device. Larger networks might need a bigger hub with more ports.

To communicate across the network, devices send data in chunks called 'packets'. When a hub receives a data packet from any computer, it immediately copies it and broadcasts it to all connected devices. The packet includes a destination address, so the receiving computer knows to open it and all other computers discard it.

This is a cheap and effective way of transmitting data, but it is a little inefficient. Even if the data is meant to go to only a single computer, the hub will send it to all of them at once.