Java Collections Framework is a pivotal feature of Java which provides a set of classes and interfaces that implement commonly reusable collection data structures. It is a unified architecture for representing and manipulating collections, allowing them to be manipulated independently of the details of their representation.

Core Interfaces and Classes

At the heart of the Java Collections Framework are the core interfaces — Collection, List, Set, Queue, and Map — and their various implementations like ArrayList, LinkedList, HashSet, LinkedHashSet, TreeSet, PriorityQueue, and HashMap among others.

Collection Interface

The Collection interface is the root interface of the Java Collections Framework and does not come with direct concrete implementations. It declares essential operations such as adding and removing elements, determining the size of the collection, and checking if an element or a collection of elements exists within the current collection.

List Interface