What is a void pointer and what is a null pointer?

So I was going through some interview questions and I came across one about void and null pointers, which claims:

a pointer with no return type is called a null pointer. It may be any kind of datatype.

This confused me thoroughly! It seems void and null could be used interchangeably according to this question, and I don't believe that to be correct. I assumed void to be a return type and null to be a value. But I am just a code-rookie and am not sure I am right.

Please express your views as to what a null pointer is and a void pointer is. I am not looking for difference between null and void.