Compare & Contrast OS Schemas

I am taking an introduction to UNIX class and part of this week's assignment is to compare and contrast the Windows OS schema (of the PC you are currently using - in my case XP Pro) with the Knoppix 3.6 Linux schema. (We are using Knoppix as an alternative to UNIX for classroom exercises.)

My question is: what are the schemas? I have been unable to find much info in our text book (Guide to Linux Shell Script Programming) and Google finds 1000's of hits but most apply to databases.

Is the schema nothing more than the directory structure of the OS and I'm making this harder than it is? Or am I missing something very obvious? Any help is greatly appreciated.

Thanks.