* Moves in a straight line. Constant velocity means both constant speed *and* constant direction.

* Has zero acceleration. Acceleration is the rate of change of velocity. If velocity is constant, there's no change, so acceleration is zero.

Here's a simple way to think about it:

* Constant speed: The object is traveling at the same pace (like a car on cruise control).

* Constant direction: The object is moving in the same direction (not turning or changing its path).

Let me know if you have any other questions!