Periapsis is the point in an orbit where an object is closest to the body it is orbiting. For example, in the case of a satellite orbiting Earth, the periapsis is the point where the satellite is nearest to Earth. This distance can affect the satellite's speed and gravitational forces acting upon it. In different types of orbits, the term periapsis can be specified further. For instance, in a planetary orbit, it is called perihelion when referring to the Sun, and perigee when referring to Earth. Understanding periapsis is crucial for planning space missions and satellite operations.