The pattern ususally refers to the oval or "racetrack" pattern flown over the field, with the long way going from side to side, and the close leg being over the runway. It's the "landing pattern" with out landing. Assuming the wind is down the runway, this gives you a downwind leg, a cross wind leg and an upwind leg. A "left hand" pattern is turning left, and a "right hand" pattern is turning right.