Deque (Doubly ended queue) is a data structure that allows you to insert and remove elements from both the ends. The Deque interface was introduced in Java 6 in java.util.collection package. The Deque interface extends the Queue interface. Hence, all methods provided by Queue are also available in the Deque interface.
There are three concrete implementations of the Deque interface: LinkedList, ArrayDeque, and LinkedBlockingDeque .