Differences in cars

What are the main differences in the Mazda 3 4 door; Mazda 6 sports sedan; mazda 6 5 door. other than the hatchback for the later of the 3

Thanx!

well lets see, you could be talking about any differences but to be vague such as your question

the engine goes from a 2.3L i4 on the mazda 3 models to a 3.0L V6 on the sport models (sedan and hatchback)

your also looking at fuel economoy differences, cargo space etc...

A little more specific and maybe I can help out more