The term "Milky Way," first appeared in Classical Antiquity to describe a band of light in the night sky.
It has since been adopted as the name for our galaxy.
The Milky Way is made up of a Galactic Center shaped like a bar and a Galactic Disk made up of spiral arms, all surrounded by a Halo made up of old stars and globular clusters.
The Milky Way Galaxy's Galactic Disk is approximately 100,000 light-years in diameter and 1,000 light-years thick.