What is the difference between int (*cmp)(void) and int *cmp(void)?

Question

What is the difference between

extern int (*func)(void);

and

extern int *func(void);

Thanks

Answer 1

extern int (*func)(void);

declares func as a pointer to a function which takes no arguments and returns an int value.

extern int *func(void);

is a forward declaration (a.k.a. a protptype) of func as a function that takes no arguments and returns a pointer to an int.

The first declares a variable, the second declares a function.