A variable that simply holds the memory address of another variable or data structure is (partially correct) a pointer.

However a pointer can also contain the address of a function (or method etc.) or even a machine instruction (eg. "PC" or Program Counter on some architectures).

It can also be null.

To nitpick on the word "simply" it could also be argued that a variable that simply holds the memory address of another variable or data structure is a reference.

This all somewhat depends on your choice of programming language, as the definition is has a bit of fluidity.