A: Both stacks and queues are fundamental data structures used for organizing and managing data. Here are the key differences: Stack: LIFO (Last-In, First-Out) order: The last element added is the first one to be removed. Operations: Push: Adds an element to the top of the stack. Pop: Removes the top element. Common use cases: Function call stack, expression evaluation, undo functionality. Queue: FIFO (First-In, First-Out) order: The first element added is the first one to be removed. Operations: Enqueue: Adds an element to the back of the queue. Dequeue: Removes the front element. Common use cases: Task scheduling, breadth-first search, printer job queue.