What is the Difference Between Stack and Queue?

The main difference between a stack and a queue lies in their insertion and deletion operations, which are based on the Last In First Out (LIFO) principle for stacks and the First In First Out (FIFO) principle for queues. Here are some key differences between stacks and queues:

• Data Structure: Both stacks and queues are linear data structures that store elements in a specific order.
• Inserting and Deleting: In a stack, elements can only be inserted and deleted from the top, while in a queue, elements can be inserted from the rear and deleted from the front.
• Operations: The insertion operation in a stack is called "push" and the deletion operation is called "pop". In a queue, the insertion operation is called "enqueue" and the deletion operation is called "dequeue".
• Variants: Stacks do not have variants, while queues can be of three types: Circular Queue, Priority Queue, and Double-Ended Queue.
• Applications: Stacks are often used for recursive algorithms or for maintaining a history of function calls. Queues are often used in multithreaded applications, scheduling tasks, routers, switches, and maintaining playlists in media players.

In summary, stacks and queues are both linear data structures, but they differ in their insertion and deletion operations, as well as their applications. Stacks follow the LIFO principle and are used for recursive algorithms and function calls, while queues follow the FIFO principle and are used in scheduling tasks, networking, and other sequential processing scenarios.

Comparative Table: Stack vs Queue

Here is a table highlighting the differences between stack and queue data structures:

In summary, the main difference between stack and queue data structures is the order in which elements are accessed and removed. In a stack, the last element added is the first one to be removed, while in a queue, the first element added is the first one to be removed.