tell me about broad cast domain and colission domain?

Answer 1

A collision domain is a network where two or more packets can collide because they are being sent at the same time. Most computer networks are ethernet networks which can only handle one packet at a time and are called CSMA/CD networks.

A broadcast domain is where any computer on a network segment can directly transmit to any other computer without going through a router. Multiple logical networks can share the same physical device but be on different broadcast domains. Examples of this are VLANs, computers with a different subnet mask.