A nitpick to your nitpick: they said "memory location". And yes, a pointer always points to a memory location. Notwithstanding that each particular region of memory locations could be mapped either to real physical memory or any other assortment of hardware.
A nitpick to your nitpick: they said "memory location". And yes, a pointer always points to a memory location. Notwithstanding that each particular region of memory locations could be mapped either to real physical memory or any other assortment of hardware.
No. Neither in the language (NULL exists) nor necessarily on real CPUs.
NULL exists on real CPUs. Maybe you meant nullptr which is a very different thing, don't confuse the two.
You can point to a register which is certainly not memory.