SERPS with quotes versus without

what is the diff?

[travelin cat]

I noticed that we place very well for certain phrases with quotes like this: "search phrase" but are no where for searches for the term search phrase without them.

How does G view searches with quotes differently then without?

[kevinpate]

"big red widget" =
I want pages containing these terms, in this order

big red widget =
I want pages containing these terms, in any order

And depending on one's default settings, it might even be that
big red widget =
I want pages containing, at least, one of the terms