Orbit & Escape.

Fire a cannonball fast enough sideways and, as it falls, the ground curves away beneath it just as fast as it falls — it keeps missing the surface. That is an orbit: continuous free fall with enough sideways speed to keep missing the ground.

Slower than circular speed, the launch point is the orbit's farthest point (apocenter) and the near side may dip below the surface. At exactly circular speed, altitude never changes. Faster than circular, the launch point becomes the orbit's closest point (pericenter) and the far side climbs higher — up to escape speed, where the path no longer closes.

Escape speed is about 1.414× circular speed at the same altitude, not a single fixed number. Starting higher up, both circular and escape speed are lower.