Exam topic and a bit in the cake

Hello;
I didn't know where to post, so sorry if I'm in the wrong place.

I received my exam topic on Saturday, and since my teacher wasn't there, I didn't get any explanation. I have 3 to 6 weeks to put together a minimum 20-page document, and I wanted to know what I should do with this topic:

Characterize the different categories of computer systems (mainframes, minicomputers, workstations, microcomputers, embedded systems, etc....)

Since I'm having a bit of trouble in class, I don't know exactly what I need to characterize and differentiate, so if someone could explain it to me, that would be great.

Thanks, everyone.