The First Law of Newton, also known as the Law of Inertia, states that an object at rest will remain at rest, and an object in motion will continue to move at a constant velocity unless an external force acts upon it.
Inertia is the tendency of objects to resist changes in their state of motion.
This law is fundamental in classical mechanics, laying the groundwork for understanding the behavior of objects under the influence of forces, and is crucial in the fields of physics and engineering.