TRACON is an acronym for Terminal Radar Approach Control. They are
the part of the Air Traffic Control system that takes care of aircarft
approaching and departing from airports. It usually has a coverage from 5
to 50 miles around the designated airport areas.
TRACON controllers are responsible for guiding and lining aircraft up with airport
runways before handing them off to the airport's Control Tower. Departing
aircraft are handed off to En Route Controllers. The primary responsibility
of TRACON controlloers (and most of the ATC system) is to prevent collision
between aircraft by ensuring and maintaining separation at least to the minimum as specified by the FAA.
Additionally, TRACON controllers are responsible for guiding pilots safely
during instrument conditions while they are on their designated airspace, also, during times of congestion, they must keep them in holding pattern and select the order in which they are to land to keep with the airport's capacity.
In some particularly crowded areas, TRACON for different airports that would have overlapping airspace can be consolidated in a single organization for improved handling.
Source: FAA web site http://www.faa.gov
TRACON is also the name of a game that simulates, well, a TRACON. The purpose of this game is to guide the aircraft safely as they take off and land in your designated airports. The first two versions of this game were released in the late eighties.