What is the difference between a stack and a queue?

 

Both stacks and queues are data structures used to organize and store data, but they differ in how they add and remove items.

A stack is a Last-In-First-Out (LIFO) data structure, which means that the most recently added item is the first one to be removed. It is like a stack of plates, where the last plate added is the first one to be taken off. A stack has two primary operations: push (add an item to the top of the stack) and pop (remove the top item from the stack). Stacks are often used in programming for tasks such as function calls and expression evaluation.

A queue, on the other hand, is a First-In-First-Out (FIFO) data structure, which means that the first item added is the first one to be removed. It is like a line of people waiting for a movie, where the first person to arrive is the first one to get in. A queue has two primary operations: enqueue (add an item to the back of the queue) and dequeue (remove the front item from the queue). Queues are often used in programming for tasks such as task scheduling, message passing, and breadth-first search.

In summary, the key difference between a stack and a queue is the order in which items are added and removed. Stacks use a LIFO approach, while queues use a FIFO approach.