Stack (abstract data type)
In computer science, a stack is an abstract data type that serves as a collection of elements with two main operations: Push, which adds an element to the collection, and Pop, which removes the most recently added element. Additionally, a peek operation can, without modifying the stack, return the value of the last element added (the item at the top of the stack).
Source: Wikipedia — Stack (abstract data type) (CC BY-SA 4.0)