Here's how it works:

* Occultation: When one celestial object passes directly in front of another, from the perspective of an observer.

* Stars: In this case, one star is moving in front of the other.

During an occultation, the star in the background is temporarily blocked from view by the star passing in front. This can be observed as a sudden dimming or disappearance of the background star.

Occultations are not limited to stars. They can occur between:

* Planets and stars

* Moons and stars

* Asteroids and stars

Important Note: Occultations are usually observed from Earth, and the apparent motion of the stars is affected by our planet's movement.