Messier 83, the Southern Pinwheel Galaxy, is one of the largest and closest barred spiral galaxies to us. At 15 million light-years away, it is one of the most conspicuous galaxies of its type in our skies. It's in the constellation of Hydra (The Sea Serpent) and is a prominent member of a group of galaxies known as the Centaurus A/M83 Group, which also counts dusty Centaurus A and irregular NGC 5253 as members.
Spiral galaxies come in a range of types depending on their appearance and structure -- for example, how tightly wound their arms are, and the characteristics of the central bulge. Messier 83 has a "bar" of stars slicing through its center, leading to its classification as a barred spiral. The Milky Way also belongs to this category.