“Normally, the computer stores return addresses in a group of sequential locations known as a stack. The most recent return address is stored at the “top of the stack.” The memory stack works just like a stack of dinner plates: items are always added or removed from the top—a last-in, first-out storage system that works perfectly for storing the return addresses of nested subroutines, because a subroutine is never finished until all of its nested subroutines are finished.”