address space

This term is a technical specification used primarily in computer science and systems architecture. It describes the theoretical limit of memory that a CPU can reference, determined by the width of the address bus. For example, a 32-bit system is limited to a 4 GB address space.

In modern operating systems, a distinction is made between the physical address space, which refers to the actual hardware RAM installed, and the virtual address space, which is a logical abstraction allowing processes to behave as if they have a contiguous block of memory regardless of physical fragmentation.