A model used to illustrate memory. The model compares memory to a stack of cafeteria trays. New pieces of memory are added to the "top" of the stack, thus displacing the ones at the "bottom" in sequential order. In this model, access to memory is only from the "top". The model is often used to explain short-term memory in humans.
PUSH-DOWN STACK: "The push down stack model assumes that memory is only accessible from the "top"."