Here's a breakdown of the law:

* Inertia: This is the tendency of an object to resist changes in its motion. An object at rest wants to stay at rest, and an object in motion wants to stay in motion at the same speed and in the same direction.

* Constant velocity: This means both the speed and direction of the object remain the same.

* Outside force: A force is a push or pull that can cause a change in an object's motion. To change an object's velocity, a force must act upon it.

In simpler terms: If nothing pushes or pulls on an object, it will keep doing what it's doing. If it's standing still, it'll stay still. If it's moving, it'll keep moving at the same speed in the same direction.