Salam Friends

I have studied a chapter on the topic of Deen and Mazhab, but still my concept is not clear.
Can anybody define what is Deen and what is Mazhab? Their formal definitions and an example as well. Also tell me how to differentiate between these two?
you can reply in URDU or ENGLISH whatever medium you want to use, i wont be having any problem because I am intending to Opt for Urdu as a medium for Islamiat.

Regards
Muhammad Adnan