Queue

Synonym
FIFO (First In First Out) List

Definition
A Queue is an ordered collection of items in which the items are inserted from one end called the front end and the items are deleted from the other end called the rear end.

Applications
1) Priority Queue
A type of queue called priority queue is very useful when the items have to be sequenced according to some order ex: ascending or descending or in an order according to a given priority.
2) Algorithms
Queues are used in thousands of algorithms like breadth first traversal, prim's algorithm, etc.