Access Order
Stack: Follows the "Last In, First Out" (LIFO) model, meaning the last element added is the first one to be removed.
Queue: Follows the "First In, First Out" (FIFO) model, meaning the first element added is the first one to be removed.
Main Operations
Stack: Has two main operations - push to add an element to the top (or topmost) of the stack and pop to remove the element at the top of the stack.
Queue: Has two main operations - enqueue to add an element to the end of the queue and dequeue to remove the element at the front of the queue.
Common Applications
Stack: Often used in situations like managing function calls (Call Stack) in JavaScript, browser history management, syntax checking, and algorithms that involve recursion.
Queue: Commonly used in processing tasks in a first-come-first-served manner, such as processing queued data in cloud applications, managing tasks waiting for execution in systems, and in algorithms related to breadth-first search.
Data Structure
Stack: Easily implemented using either an array or a linked list.
Queue: Can also be implemented using either an array or a linked list.
Real-World Examples
Stack: A real-world example is stacking CDs or DVDs in a stack where you can only remove or place a disc at the top of the stack.
Queue: A real-world example is a checkout line at a store where the person who arrives first is served first.
In summary, the main difference between Stack and Queue lies in their access order, primary operations, and typical applications. Stack follows the "Last In, First Out" (LIFO) principle, while Queue follows the "First In, First Out" (FIFO) principle. Both have their distinct use cases and applications in programming and everyday life.