What is the difference between hub and switch?

Hub is a layer 1 device. It will out the signal from all of its port except the one from where its insert. It is unable to detect the collision. It works on single collision and single broadcast domain.

A Switch is layer 2 device. It maintains a CAM table that stores the MAC address of devices attached on its port. CAM table is used to make the forwarding decision. It works on per port collision and single broadcast domain.