The Milky Way galaxy includes three main stellar components, in order of
decreasing mass: the disk, the bulge and the halo. Bulge and halo are
the oldest ones, according to our understanding, with the halo being
likely older than the bulge, but about 30 times less massive.
Therefore, being the first massive component to be set in place, the
bulge plays a crucial role in the formation of the Milky Way galaxy.
Our understanding of the stellar population of the Galactic bulge has
improved significantly in the last 5-10 years, thanks to large near
infrared photometric surveys such as VVV, coupled to massive
spectroscopic campaigns such as ARGOS, Gaia ESO, GIBS and APOGEE.
I will review the recent observational results, and the currently open
questions especially regarding the innermost region: the so-called
Nuclear Bulge.