As measured against the fixed stars, planets typically appear to move eastward. But, sometimes, they seem to pause briefly in this eastward motion and, for some months, to move westwards (backwards) in front of the stars. Then they pause again. And then they start moving eastward again. Astronomers (and astrologers) call their change in direction retrograde motion.
Astronomers also use the word retrograde to describe true backward motion among planets and moons.