Stacks and queues are fundamental data structures used to manage collections of elements. A stack follows the Last In, First Out (LIFO) principle, meaning the last element added is the first one to be removed. It is often used for tasks such as reversing data, function calls, and undo operations. A queue, on the other hand, follows the First In, First Out (FIFO) principle, where the first element added is the first one to be removed. Queues are commonly used in scenarios like task scheduling, data buffering, and handling requests in a system. Both structures enable efficient element access and manipulation through specific operations like push and pop for stacks, and enqueue and dequeue for queues.