When used as a function return type, the void keyword specifies that the function does not return a value. When used for a function's parameter list, void specifies that the function takes no parameters. When used in the declaration of a pointer, void specifies that the pointer is "universal."

If a pointer's type is void*, the pointer can point to any variable that is not declared with the const or volatile keyword. A void* pointer cannot be dereferenced unless it is cast to another type. A void* pointer can be converted into any other type of data pointer.

A void pointer can point to a function, but not to a class member in C++.

You cannot declare a variable of type void.

// void.cpp
void vobject;   // C2182
void *pv;   // okay
int *pint; int i;
int main() {
   pv = &i;
   // Cast optional in C required in C++
   pint = (int *)pv;
}

Keywords
Built-in types