Programming language
Stack-based languages look at some of the program's memory like a stack of cards. There are very few things that can be done with a stack. A data item can be put on the top of the stack. This operation is generally called "push". A data item can be removed from the top of the stack.  This is called a "pop".  You can look at the item at the top of the stack without removing it.  This is called a "peek".