|May I recommend you do some research through www.google.com before you come in here and ask for help.|
Nobody here is going to do your homework for you and most, if not all of us, know enough to know you're just being lazy because we know there's a ton of info on the web regarding the OSI model.
Oh and by the way, try using proper grammar....you know, capitalization, punctuation, etc. Your complete lack of grammatical correctness proves you're lazy and is terribly unprofessional. If you want to be taken seriously, then behave in a more professional and mature fashion.