Derivation in Arabic is taking one or more words from another word, and it’s fundamental for generating new words from a single root Example : Study : yadros يَدْرُس A lesson : dars درس Teacher : modaris مدرس School : madrasa مدرسة Teach : yodaris يُدَرِّس And the original root is (lesson) : dars درس 
do you have another example about derivation ?