Astrometry is the branch of astronomy for measuring the position of celestial bodies such as stars. I've also seen it described as the precise measurement of bodies on the Celestial Sphere. The first definition includes some resulting analysis/interpretation.
Precise measurement of the apparent motion of a star in the sky can reveal its distance through Parallax, or can reflect actual movement, showing something of its motion vector, or can indicate an Astrometric Binary or the presence of an Extra Solar Planet.
Bonner Durchmusterung Catalog (BD)
European Southern Observatory Very Large Telescope (ESO VLT)
Extra Solar Planet
Position-Position-Velocity Space (PPV)
SkyMapper Southern Survey (SMSS)
Stellar Distance Determination
Stellar Mass Determination
Stellar Parameter Determination