The <stack>
header declares the stack
container adapter. This class template
is not a container in its own right, but adapts other containers to
present the behavior of a stack.
A stack is a sequence of items that supports insertion and removal at one end. Because the last item inserted into a stack is the first item removed, a stack is sometimes called a LIFO (last-in, first-out) container.
See Chapter 10 for information about containers.