Spiral galaxies, which number about half of all galaxies, are shaped like a disk, resembling a pinwheel with arms which spiral outward as it rotates. Spiral galaxies contain middle-aged stars along with clouds of dust and gas. The Milky Way Galaxy is a spiral galaxy, and is only one of the uncountable galaxies. Elliptical galaxies contain older stars and very little dust and gas. They range in their shape from round to flattened, oval-shaped pancakes.
Irregular galaxies have an undefined shape, and are full of young stars, gas, and dust.
It wasn't until this century that astronomers understood the nature of the galaxy that surrounds us. All of the stars that you see with just your eyes on any given night belong to the Milky Way Galaxy. Through an amateur astronomer's telescope, most galaxies look like small smudges of light aginst a black background. Even the view through a large telescope doesn't show the galaxies as they often look like in pictures taken in space. The Hubble Space Telescope takes spectacular photographs and collects valuable information about even the most distant galaxies, forcing astronomers to change their ideas of galaxy formation.