The "First Law" refers to Isaac Newton's First Law of Motion, which states that an object at rest will remain at rest, and an object in motion will continue in motion at a constant velocity unless acted upon by a net external force. This principle highlights the concept of inertia, which is the tendency of objects to resist changes in their state of motion. In practical terms, the First Law explains why a soccer ball remains stationary until kicked and why it continues to roll until friction or another force stops it. This foundational concept is crucial in understanding the behavior of objects in physics and is a key element of classical mechanics.