whats the difference?

does anyone know what the difference in Whey protein isolate and whey protein concentrate is?  I've been enjoying some shakes by Chike, and the first ingredient is the isolate, the second is concentrate.  what's the difference?

I can't drink it, but I recall that the isolate is the superior....

isolate is more "pure" 

It contains more protein and less fat and lactose per serving. 

Thanks!