Collision domain is a logical area where the packets/frames get collied each other in a CSMA/CD ether network. All the hosts in that area trying to grab the access of the network/carrier to send out its data.
In the case of Hub all the ports/host are in the same collision domain, means that only on host can able to send the data. But in the case of switch each port in the switch has seperate collision domain as it has the intelligence upto
MAC layer.

Broadcast domain is logical area, where the brocast packets are heard by the hosts.
In the case of Hub and all the ports/host are in the same broadcast domain.

VLAN configs in the siwtchs can able to divide the broadcast domain in the ethernet segment.