nMemory references are dynamically translated into physical addresses at run time
ua process may be
swapped in and out of main memory such that it occupies different regions
nA process may be broken up into pieces (pages or segments) that
do not need to be located contiguously
in main memory
nHence: all pieces of a process do not need to be loaded in main memory
during execution
ucomputation may proceed for some time if the next instruction to be fetch (or the next data to be
accessed) is in a piece located in
main memory