A double-ended queue, or deque, is a type of queue that allows elements to be added or removed from either end of the queue

A deque can be implemented using a variety of data structures, such as arrays, linked lists, or circular arrays

Deques have a number of advantages such as being more efficient for inserting and deleting elements at both ends of the queue.

A deque can have a fixed size, or it can be dynamic and expand as needed

A deque can be used to store a variety of data types, such as integers, strings, or objects

The common operations which can be performed on deques are: insertFront, insertL,ast, deleteLast, etc

Deque can be used as stack and queue because it supports both  operations.