The term "pole position" comes from the horse racing term where the number one starter starts on the inside next to the inside pole.
The term made its way, along with several other customs, to auto racing. In circuit motorsport, a driver has pole position when he or she starts a race at the front of the grid. Grid position is usually determined by a separate qualifying session where drivers try to set the fastest lap, or based on their position in the previous race(s).
Different motorsport series use different formats for determining which driver has the opportunity to start from pole position.
The pole position is currently determined by a two-lap time trial (one lap on road courses). The fastest lap time is used. Before 2001, NASCAR used a two day qualifying format in its national series. Before 2002 only one lap was run on oval tracks except short tracks and restrictor plate tracks.