What does “Class* &cls” mean in C++'s function definition?

Question

I know Class *cls is a pointer, and Class &cls takes the address, but what is

void fucction1( Class *&cls)

If I have Class c

Answer 1

For a type T, T* is a pointer to an object of type T, so Class* is a pointer to a Class object.

For a type T, T& is a reference to an object of type T, so putting them together, Class*& is a reference to a pointer to a Class object.