Technology Fundamentals

Queue

Definition

A queue is an abstract data structure, somewhat similar to a stack. Unlike a stack, a queue is open at both its ends. One end is always used to insert data (enqueue) and the other is used to remove data (dequeue). A queue follows the First-In, First-Out (FIFO) methodology.

Why It Matters

Queues are used in many computing scenarios where tasks or data need to be processed in the order they are received, such as handling print jobs, processing requests on a web server, or managing tasks in a background job system.

Contextual Example

A printer's job queue is a perfect example. Documents are printed in the order they were sent to the printer. The first document sent is the first one to be printed.

Common Misunderstandings

  • A queue is FIFO (First-In, First-Out), like a line at a grocery store.
  • A stack is LIFO (Last-In, First-Out), like a stack of plates.

Related Terms

Last Updated: December 17, 2025