Laravel Model Events - perform actions on specific column update

as we all know Laravel has model events which are fired on certain instances, and we can perform actions on them, like created, creating, saved, saving, etc. What I want to know is that how can we know which column was updated on lets say 'saved' event like a user was updated and of course saving and saved events were fired, inside these events can one know which column was updated and perform actions accordingly ? Thanks in advance.

via Chebli Mohamed