Give brief comparison of broadcast, unicastand multicast?

In broadcast the message is transmitted from one to all , in uni cast we have one to one transmission and in multicast we have transmission from one to many.

Explanation:

If we take the example of a simple messaging application it will be clear. If a message is exchanged between one person to another, then it is uni casting. If a person sends a message to all the persons in his contact list then it is broadcasting and  if a person sends messages to select persons in his contact list then it is multi casting. In multi casting management of the group is required regarding who can receive messages which is not required in broadcasting.

so much for the extra points :

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