What is Collection?

A collection object(technically speaking data-structures) represents a container for objects,which generally expands itself to accommodate these objects.One has not be bothered about how many objects a collection object can contain.The collection classes like Vector,Hashtable(both are in Java 1.1) and ArrayList,HashMap(both are in Java2)are sophisticated way of holding objects.One can pick any of the collection objects as per need and sometimes on choice.