The velocity formula expresses the relationship between displacement, time, and velocity, mathematically defined as $$v = \frac{\Delta x}{\Delta t}$$, where $$v$$ is the velocity, $$\Delta x$$ is the change in position, and $$\Delta t$$ is the change in time. This formula is crucial for understanding motion because it provides a clear way to quantify how fast an object moves in a specific direction over time. Velocity, being a vector quantity, emphasizes both speed and direction, which are essential for analyzing relative motion between objects in different frames of reference.