A Tractor beam is a technology found in science fiction stories, which involves a beam of energy that applies an attractive force on an object it is targeted at. The typical example is one spaceship using a tractor beam to grab another and either capture or tow it.
A variation on the tractor beam is the Pressor Beam, which applies a repulsive force on an object it is targeted at to push it away.
The concept of tractor and pressor beams was popularized in the Lensman novels written by E.E. "Doc" Smith.