Differences M sport and M?

[M4YHEM]

Hey guys a whole bunch of my friends came over last night and we were talking about M's. So one of my friends said he hates when M packages cars act like M's and swear their the real thing. To my knowledge I thought they were basically the same thing but a few differences. We had a major debate about this and this shit went on for hours over our basketball games. Can anyone give me more info? Or their opinions cause I know there's a differences from a M6 and m640i sport. Just looking to slap him in the face with knowledge from others cause I sure as hell am lost. Thank you in advance for all the help.

[mkoesel]

https://en.wikipedia.org/wiki/BMW_M#..._M-badged_cars
https://en.wikipedia.org/wiki/BMW_M#..._M_Performance