unity - When should I use velocity versus addForce when dealing with player objects?

I'm confused about these two methods in the Unity framework. Both make the player object move, stop, change direction, etc. When should one be used over the other and when is one appropriate?

Answer

You'd use velocity to move the object at a constant rate (for example a bullet) and AddForce() to add movement (for example a spaceship thruster). Also note there are two "types" of movement; force and impulse. For a spaceship thruster you'd use impulse.