Depends on your interviewers. Some people I've talked to say it was super conversational, but mine was very strict question and answer, i.e. they'd say "alright question number one: bla bla bla", I'd give my answer, and the next interviewer would say "okay I have question number 2".
I've heard from current students that they have to ask questions that way because the interviewers used to ask whatever questions they wanted, but some interviewees got upset at some of the questions, so now they have a list they have to read from.