Also sometimes used to refer to the oar as a whole stroke - the act of moving the blade through the water.
Sculling refers to rowing in which each rower controls two oars - one in each hand.
Sweep rowing refers to rowing in which each rower operates one long oar on a single side of the boat. Sculling shells are referred to as singles, doubles, quads, etc. while shells used for sweep rowing are referred to as pairs, fours, and eights. The back of the boat is referred to as the stern, and the front of the boat is refered to as the bow. In sweep rowing these terms are also used in reference to rowers who row only one side of the boat. The rowing ergometer is a machine consisting of a seat running on a metal rail and a handle attached to a large fan.