A colleague asked about the distinction between "differ from" and "differ with."
In R.W. Burchfield's update of Fowler's usage guide, he writes that "in the sense to be unlike, distinguishable," differ is followed by from. If the writer means to show disagreement or a difference of opinion, differ is followed by with. Bryan A. Garner says that differ from "typically appears whenever two things are unlike."
Here are examples:
My home computer differs from the one I use at work; mine is a PC, and the one I use at work is a Mac.
I differ with my colleague about computers: I think my Mac is better than his PC.