Java Collection Framework has four basic interfaces - Collection, Set, List and Map
Collection is the root of the collection hierarchy. A collection represents a group of objects known as its elements.
Set is a collection that cannot contain duplicate elements. This interface models the mathematical set abstraction and is used to represent sets, such as the deck of cards.
List is an ordered collection and can contain duplicate elements. You can access any element from it’s index. List is more like array with dynamic length.
Map is an object that maps keys to values. A map cannot contain duplicate keys: Each key can map to at most one value.
