  Sgr A* is the unique 1 Jy flat spectrum radio point source located at the
dynamical center of the Galaxy and in the very center of the central star
cluster. Due to its unusual appearance it has long been speculated that this
source is powered by a supermassive black hole. The enormous increase in
observational data obtained for Sgr A* in recent years has enabled us to
develop, compare and constrain a variety of models for the emission
characteristics of this source. Because of its relative proximity and further
observational input to come Sgr A* may therefore become one of the best
laboratories for studying supermassive black hole candidates and basic AGN
physics. This paper briefly summarizes our current understanding of this
enigmatic radio source and compares various models, i.e. disk/jet and
wind-accretion models.
