Virtual address space  From Wikipedia, the free encyclopedia
Jump to: navigation, search "Virtual address" and "virtual
addressing" redirect here. For other uses, see Virtual address
(disambiguation). Virtual address space and physical address
space relationship.svg  In computing, a virtual address space
(VAS) or address space is the set of ranges of virtual addresses
that an operating system makes available to a process.[1] The
range of virtual addresses usually starts at a low address and
can extend to the highest address allowed by the computer's
instruction set architecture and supported by the operating
system's pointer size implementation, which can be 4 bytes for
32-bit or 8 bytes for 64-bit OS versions. This provides several
benefits, one of which is, if each process is given a separate
address space, security through process isolation.   In the
following description, the terminology used will be particular
to the Windows NT OS, but the concepts are applicable to other
virtual memory operating systems