Hub is a network device used for directly connecting computers. It acts as a center for LAN. It can be considered a multi-port repeater.

Hub works on a physical layer. It receives bits and sends them to all the devices connected to it. It has no routing table, it can't filter data. When bits reach a device, the device checks their destination address and matches it to its own MAC address.

If 2 devices send data simultaneously, collision occurs and data gets lost. Devices then have to wait a certain amount of time to try again.