Pointers are a part of C++ programming that can cause grief though not as much as in C, where to do anything non trivial you have to use pointers. Pointers aren’t that bad, but if you’re new to them they will cause you troubles. It is all to easy to write bad code with pointers.
ESP in action
Let’s say we want to quickly discard 3 items we pushed earlier onto the stack, without saving the values (in other words “clean” the stack).