Ans:
To over come the limitations of arrays we should go for collection.
If we want to represent group of individual objects in a single entity then we should go for collection. Collection interface and is a root interface of collection framework.
Collections are growbable in nature, based on requirement we can increase or decrease the size of collections; we hold both homogeneous & heterogeneous elements.
Every collection class implemented based on some data structure, hence readymade method support is available for every requirement, being a programmer we have to use this method and we are not responsible to participate implementation.