What is domain?
A Windows domain is a form of a computer network in which all user accounts, computers, printers and other security principals, are registered with a central database located on one or more clusters of central computers known as domain controllers
Broadcast is a type of communication, where the sending device send a single copy of data and that copy of data will be delivered to every device in the network segment. A layer two broadcast goes to every host in the same LAN/VLAN
Broadcast domain is a group of nodes where they can hear each other by broadcast.
Hub creates collision domains
Switch separates collision domains by creating Source address table (SAT)
Routers separates both collision domains and broadcast domains.
The definition of a collision domain is a set of LAN devices whose frames could collide with one another. This happens with hubs, bridges, repeaters and wireless access points as only one device can send and receive (half duplex). If more than one device tries sending or receiving, the information is lost and irrecoverable it will need to be resent. This can slow down network performance along with making it a security threat.
A hub is considered a layer one device of the OSI model; all it does is send frames out on all ports including the port in which the frame was received on. This causes a collision domain because only one device can send at the same time. This also shares the bandwidth between of all devices connected to that collision domain. These devices can inefficiently use that bandwidth because of the CSMA/CD and jamming signals that occur when a collision happens.
B