Rectilinear Translation-Occurs when all points on a body or object move in a straight line so the direction of motion does not change, the orientation of the object does not change, and all points on the object move the same distance.

Curvilinear Translation-Occurs when all points on a body or object move so that the orientation of the object does not change and all points on the object move the same distance. The lines created by the points are curved rather than straight.