Confusing in Address

Hi, all I'm confused with different addresses in Linux, such as virtual address and hardware address. For example, which kind of address one can get when using "&num" in application layer programming? How about that in kernel, such as in device driver? Which kind of address one can get when using "void _ _user *to" in device driver? And which kind of address the kernel is working with when using "mmap"? And which kind of address we are talking about when divide the memory into user space and kernel space? It's quite tedious but thank you so much for helping me!