Page "Central processing unit" Paragraph 32

Integer range can also affect the number of locations in memory the CPU can address ( locate ).

For example, if a binary CPU uses 32 bits to represent a memory address, and each memory address represents one octet ( 8 bits ), the maximum quantity of memory that CPU can address is 2 < sup > 32 </ sup > octets, or 4 GiB.

This is a very simple view of CPU address space, and many designs use more complex addressing methods like paging to locate more memory than their integer range would allow with a flat address space.