Why does the stack address grow towards decreasing memory addresses?

Question

I read in text books that the stack grows by decreasing memory address; that is, from higher address to lower address. It may be a bad question, but I didn\'t get the concep

Answer 1

Nowadays it's largely because it's been done that way for a long time and lots of programs assume it's done that way, and there's no real reason to change it.

Back when dinosaurs roamed the earth and computers had 8kB of memory if you were lucky, though, it was an important space optimization. You put the bottom of the stack at the very top of memory, growing down, and you put the program and its data at the very bottom, with the malloc area growing up. That way, the only limit on the size of the stack was the size of the program + heap, and vice versa. If the stack instead started at 4kB (for instance) and grew up, the heap could never get bigger than 4kB (minus the size of the program) even if the program only needed a few hundred bytes of stack.