A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky.
The Milky Way is a barred spiral galaxy containing 100–400 billion stars. Its central region contains the Galactic Center Group of fast-moving S-stars orbiting Sagittarius A*, the galaxy's supermassive black hole.
