NULL Macro is simply what is defined as 0 in a macro provided by the library Null pointer is a pointer which has 0 or NULL value stored and points to nowhwere still it points to 0x00 i.e. the first...
I'll assume that you're asking your question for C type language programming. A NULL pointer is a pointer that's guarnteed to point to nothing. This may be 0 in a UNIX/Linux system or some other...