It’s a survey mission:
The catalog features multiple types of data, which means it can be used by astronomers working in different fields to understand the evolution of stars in our galaxy (and stars in general). The catalog includes data that can be used to infer the stars’ age and mass, their radial velocity (the speed at which they’re moving away from Earth), and even their temperature.
Mihai Andrei, “Almost two billion stars: Largest, most detailed star catalog to date revealed” at ZME Science (June 14, 2022)