Collection

What Is a Java Collections Framework?

•  The Java collections framework (JCF) is a set of classes and interfaces that implement commonly reusable collection data structures provided by java.

• Collections framework is a unified architecture for representing and manipulating collections.

• collection also called container because it provide container to store different different types objects in it

•  java collection framework provide Generic classes and Interface 

•  All collections frameworks in java contain the following:

1.  Interface: These are abstract data types that represent collections. all Interface derive base Interface Collection 
2.  Implementations: These are the concrete implementations of the collection interfaces. We can directly use those implemented classes in our application. 
3.  Algorithms: These are the basic methods that perform useful computations, such as searching , sorting and iterating collection, on objects that implement collection interfaces or use implemented classes. 

· You can find all collection classes and interface in java.util API

Java Collection Hierarchy is given below:

Collection Hierarchy in java