Math behind 4GB limit on 32 bit systems

Question

I have a very fundamental question relating to 32 bit memory addresses. My understanding is that 2^32 is the maximum number of possible memory addresses on a 32 bit system. Wher

Answer 1

A computer is not all memory. The 32 bits are the maximum spots for an Instruction Set to be organized. 64 bits gives you more bits to reference more memory. I think those people meant 4,294,967,296 bit combinations not bytes (8 bits).

As for the math - it seems to mean that 20 bits are reserved for other uses besides specifying a possible memory address.