What exactly do they do?
And if I was to buy one could I have two pedals plugged in at the same time?

Quote by KileManA7X
You sir, are an honorary genius! Take this badge, you made us proud!
(to the other question) Yes, you can have as many pedals as you want pluged in at the same time.
My gear:
OLP John Petrucci Sig.
Epiphone Les Paul
Epiphone Valve Jr.
Mesa/Boogie .50 Caliber+ 112
You mean the Boss pedals? They're basically just normal chorus pedals, and yes, you could have two plugged in at the same time.

I've tried the CE-5 and honestly found it far too cold, I wouldn't recommend it. I've heard clips of the CE-1 (you'll have to check eBay) and it was absolutely beautiful.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.