2012 X3 35i M Sport Package - Drive Mode Questions!

hello, I have couple questions about Drive Mode selections.
I see there are two arrow buttons for drive mode selections next to the gear shift stick.
Then, under Vehicle settings on I-Drive, there is a sport mode selection, like chassis, suspension, and both chassis and suspension modes.

Can someone explain the difference between two mode selections?
Also, what is the factory default?
and from the research on this forum, ppl talked about eco, comfort, sport mode. where do i find that?
I know most can be answered by reading the manuals, but it is my wife's car, and she has been trying this and that... and it keeps driving me crazy... haha
thank you!

The button is to taggle between eco-pro, comfort, sport and sport plus mode, default is comfort, just keep pushing the button up or down and it will go thru all the modes. The i-drive let you customize the sport mode. Some people high like a soft ride but with a stiffer steering or an less agressive transmission shift map. The eco-pro mode retards the throttle input and cutback on HVAC performance. The sport+ mode have a sportier stability system programming.

My wife's 2012 X3 35i has Normal, Sport, and Sport Plus modes.
I guess newer models renamed Normal to Comfort?
And Eco-pro is a new thing?

I think only the 2013 have the eco-pro mode and the comfort mode, I guess normal mode is the same as comfort mode.

I have a 2013 28i X3 loaner while my X5 is having its oil changed... It may be just imagination but I think the suspension tightens up during sport mode as well giving it more a sporty feel.