It's really only barely a metaphor and corresponds to a data structure known as, wait for it ... the stack. The stack's defining feature is that you can only remove things (data in various forms) from the stack in the order that they were put on the stack. A plate goes on the top of the stack and the next plate that can be removed is that plate. Take away that plate and a new plate rises up and becomes the top plate. Hot fucking shit, right?

Stacks are actually pretty neat—particularly the runtime stack, aka "the stack," that keeps a queue of a hardware instructions and generally enables your computer to do a whole bunch of things at once, or seemingly at once—and they deserve better. A stack is more than a set of rules, it's a way of thinking. This is the case with much of computer science, which is not just a realm of coded instructions, but one of entirely new ways of considering information itself. A stack of plates at a buffet line is a stack because that's just how it works out, stacks being stacks, but a stack in CS is an ingenious solution to problems that don't even exist yet.