The Stack and the heap work very closely together. With a main difference between the two being the data structures they use.
The Stack probably obviously uses a stack data type so things can be pushed on and popped off but not just removed from the middle. This is great as the main (method/function/block) whatever gets executed first in your language gets added to the stack along with its local variables all as one item on the stack. If a function is called from that main block another block is added ON TOP OF of the main block. This function block will also have all of its local variables included with it.