Generally considered to consist of
Fairfax, the cities of
Arlington,
Alexandria,
Falls Church,
Manassas and
Manassas Park, and
Prince William and
Loudoun counties on the outer edges.
Virginia exurbs of
Washington extend as far
west as
Winchester and as far
south as
Fredericksburg.
Most of the rest of the state does not consider NoVA to be part of Virginia. A favorite fact used as evidence for this point is that the first Virginia Welcome Center on Interstate 95 as you enter from the north is in Fredericksburg.