Heap is where malloc gets bytes from.
Stack is where local variables(call function) go (bottom to top) — When we call a function, we give a slice memory( stack frame).
Buffer Overflows: This design might cause a crash if we malloc too many memories and call too many functions.
Heap Overflow: e.g. too much malloc
Stack Overflow: e.g. recursion without converging to the base case
Suppose we want to swap values of x and y
Swap by value does not work:
Main:
x = 1, y = 2
Swap function:
a = 1, b = 2
to
a = 2, b = 1
Swap function stack is freed after it return
Swap by pointer does work
Even if Swap function is freed,
The values of x, y have been swaped
