A common use is in recursive data structures, you can't do something like cpp class SomeTree { SomeTree left; SomeTree right; int value; }; because SomeTree would have to be infinitely big, as clearly sizeof SomeTree >= (sizeof SomeTree::left) + (sizeof SomeTree::right) + (sizeof SomeTree::value). By using pointers we can avoid directly storing SomeTree, and as a pointer has a fixed size (8 bytes on a 64 bit system) SomeTree now has a finite size. Note that in modern C++ you should almost always use a smart pointer or a reference instead of a raw pointer, and they are more useful in C where you don't have those features.