Staff: Typically an 8+ hour day. You may have one or two assignments, maybe none at all (oh, and you can’t choose your own jobs. So if you’re stuck with government interpreting, peace!) If you do not have an assignment, typically you will go to an office where you can study up on vocabulary, receptive skills, etc. It is a steady income, but really not to hefty as far as salary is concerned. They do take out taxes for you though.
Freelance: It’s as flexible as they get. You pick your own jobs, you make your own schedule. Don’t wanna work on Fridays? K. Decline all work that is passed your way. Freelancers typically get paid more as well, sometimes double or triple the amount of a staff terp. Oh, and they get mileage too. But, you gotta do your own taxes, either yearly or quarterly, which can be a bummer.