u Ex: 16 bits are needed to address a physical memory of 64KB u lets use a page size of 1KB so that 10 bits are needed for offsets within a page u For the page number part of a logical address we may use a number of bits larger than 6, say 22 (a modest value!!) n The memory referenced by a logical address is called virtual memory u is maintained on secondary memory (ex: disk) u pieces are brought into main memory only when needed