Difference between pop and push operation in data structure through c?

Answer 1

Pushing means putting an item onto a stack (data structure), so that it becomes the stack's top-most item. Popping means removing the top-most item from a stack. (You often hear a third term, peeking, which means looking at/reading the top-most item.)

When it comes to queues, you should generally use the terms enqueueing and dequeueing instead, where the former means appending an item to a queue's "back end" and the latter means removing the item at the "front end" from the queue.

These definitions suggest that a stack (if you picture it in your head) is spatially vertical, while a queue is horizontal. Another difference is that operations on a stack always happen at the same end, while operations on a queue happen at opposite ends.

When it comes to linked lists and double-ended queues (deques), the terms push and pop are also used, e.g. in C++'s STL, where you have operations such as push_front, push_back, pop_front, and pop_back. These simply imply that items can be appended or removed at both ends.