* Newton's First Law of Motion (Law of Inertia): An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

* Constant Velocity: Constant velocity means both the speed and direction of the object are not changing.

* Balanced Forces: When forces are balanced, they cancel each other out. This means the net force (the overall force acting on the object) is zero.

Examples:

* A block sliding across a frictionless surface: Once the block is set in motion, it will continue to slide at the same speed and in the same direction because there's no friction to slow it down.

* A car traveling at a constant speed on a straight road: The engine's force pushing the car forward is balanced by the forces of air resistance and friction with the road.

Important Note: While the net force needs to be zero for constant velocity, there *might* be forces acting on the object. These forces just need to be equal and opposite, so they cancel out.