Java Collection Interface

Figure 2.9:

The Collection interface is the root interface of the collections framework hierarchy. Java does not provide direct implementations of the Collection interface but provides implementations of its sub-interfaces like List, Set, and Queue. People often get confused between the collections framework and Collection Interface. The Collection interface is the root interface of the collections framework. The framework includes other interfaces as well: Map and Iterator. These interfaces may also have sub-interfaces.

• The List interface is an ordered collection that allows us to add and remove elements like an array.
• The Set interface allows us to store elements in different sets similar to the set in mathematics. It cannot have duplicate elements.
• Queue interface is used when we want to store and access elements in First In, First Out manner. To learn more, visit Java Queue Interface