Types of Galaxies in the Universe

There are four main classifications of galaxies

Elliptical galaxies which are featureless and spiracle.

Galaxy Picture Credits

Spiral galaxy
The Hubble Heritage Team (AURA/STScI/NASA) NASA Headquarters - Greatest Images of NASA (NASA-HQ-GRIN) -http://nix.larc.nasa.gov/info;jsessionid=1sl2so6lc9mab?id=GPN-2000-000933&orgid=12http://imgsrc.hubblesite.org/hu/db/images/hs-1999-25-a-full_tif.tif

Elliptical galaxy

NASA/ESA Hubble Space telescope - http://www.spacetelescope.org/images/potw1519a/

Barred galaxy
NASA, ESA, and The Hubble Heritage Team STScI/AURA) - http://hubblesite.org/newscent....er/archive/releases/ http://www.spacetelescope.org/images/opo0501a/ ([cdn.spacetelescope.org/archives/images/screen/opo0501a.jpg direct link])

Lenticular

NASA, ESA, and The Hubble Heritage Team (STScI/AURA) - http://www.spacetelescope.org/images/opo0624a/ (direct link) http://hubblesite.org/newscent....er/archive/releases/ (direct link)
Spiral these have arms that spiral outward


Lenticular galaxies are given the symbol S0. These galaxies consist of a bright central bulge, similar in appearance to an elliptical galaxy, surrounded by an extended, disk-like structure.

Irregular galaxies are any other galaxy