The word Galaxy derives from the Greek term for our own galaxy meaning "milky circle" for its appearance in the sky. Galaxies come in three main types: ellipticals, spirals, and irregulars. Elliptical Galaxies are ellipsoidal agglomerations of stars, which usually do not contain much interstellar matter, and appear smooth like small wads in the telescope. Spiral Galaxies consist of a rotating disk of stars and interstellar medium, along with a central bulge of generally older stars. Extending outward from the bulge are relatively bright arms.
Lenticular Galaxies are disk galaxies without any conspicuous structure in their disks.
Irregular Galaxies are galactic formations that develop unusual properties due to tidal interactions with other galaxies. Learn more about nebulae here: Wikipedi Below are some galaxies I have imaged over the past few years. Click on the image to get more detailed information.