Stack pointer

In computer science, a call stack is a special stack which stores information about the active subroutines of a computer program. (The active subroutines are those which have been called but have not yet completed execution by returning.) This kind of stack is also known as an execution stack, control stack, function stack, or run-time stack, and is often shortened to just "the stack".
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<architecture, programming> (SP) A register or variable pointing to the top of a stack. If the stack is a "full" stack the SP points to the most recently pushed item, else if it is an "empty" stack, the PS points to the first empty location, where the next item will be pushed.
(1995-03-21)