Note: most of the galaxies we can easily observe are spirals (about 45%), 25% or so are S0, about 25% are ellipticals of various kinds, and a few % are irregulars. In actual fact, however, irregulars and especially (dwarf) ellipticals probably dominate the universe, but are too faint to be easily seen. Spirals are generally flashy and bright, but are probably pretty uncommon.

Spirals	Property	Ellipticals
1011 to 1012 Solar Masses	MASS	106 to 1012 Solar Masses
1010 to 1012 Solar Luminosities	TOTAL LUMINOSITY	106 to 1012 Solar Luminosities
10 to 100 kiloparsecs	ACTUAL DIAMETER	1 to 100 kiloparsecs
blue in the arms, red in the center	COLOR	mostly red
all kinds	TYPES OF STAR	mostly red, low mass stars
metal-poor in the halo, solar-type metal abundances in the disk	METALLICITY	metal-poor throughout
much in arms, little in halo	GAS AND DUST	very little to none
rigid body in bulge, constant speed in disk, random in halo	"ROTATION"	random motion throughout