This will obviously be different for everyone. I talked for about 5-10 minutes and mixed the stages on my CV with more details of why I decided to do things, what I liked, what skills I learned. Highlighted my biggest achievement and added a few things about how I am as a person.
This is a classic strengths/weaknesses question. They wanted to know two each. There was a short behavioural question for both weaknesses afterwards. I said I have a hard time saying No and want to please everyone, for example, so they asked what I would do if 10 colleagues wanted something from me at once.