Video narration
Why is the last plate you put on a stack the first one you can take off? You don't reach into the middle or lift from underneath; you add and remove plates only at the top. Computers follow this same rule in a stack. Adding an item on top is called push; removing the top item is called pop. Put down a blue plate, then white, then red. Red sits on top, so it comes off first, leaving white reachable. Each new plate covers the one before it, so you must clear the top to reach what's below. Blue stays underneath until the plates above it are gone. That order isn't a coincidence: you can only reach the top. In computing, this is last in, first out: the newest item added is the first removed. So the last plate comes off first because you can only take from the top.