Lost in the Cloud:Steam & Cloud -what the?

[jamesdietz]

I'm new to Steam thanks to CloD & know a little about Cloud , but could someone explain in layman's terms how they work together for my benefit & others?
I see I can turn the Cloud off...why would I want to do that? Does it prevent my config being changed back to default everytime I start the game? I see with it off I can no longer take screenshots on Steam ( the only place I have been able to so far as it doesn't work for me "in game,")so what other benefits do I get from being off the Cloud ( any better FPS fer instance?)With Cloud turned off will I still get updated patches automatically( I am praying for the next one ...really !) when I start the game?
Is there any advantage to just keeping the Cloud on? Does it make any difference if I specify "offline" or not in Steam.In fact does off line do anything good? Does it prevent Campaigns being continued & statistics from being tallied as in Rise of Flight off line? What's its use?
I'm sure there's more but this is a good start for someone like me who hasn't much of a clue...Thanks!