In the C programming language, a Null pointer is a variable with a value of zero or an address that refers to nothing.

To turn a variable into a null pointer, which is a predefined macro in C, use the keyword NULL.
A pointer that points nowhere is known as a null pointer.

The null pointer can be used, among other things, to initialize a pointer variable when it hasn’t yet been given a valid memory address.

When we don’t wish to give any valid memory addresses, we can pass a null pointer as an argument to a function.