Deduction (qiyās): A conclusion is drawn from premises structured to entail it, often applying a universal rule to a particular case.
Induction (istiqrāʾ): A general judgment is drawn from facts established about members of a class.
Deduction:
Every human is mortal. Zayd is human. Therefore Zayd is mortal.
Induction:
All five known students in this class are present. Therefore every student in the class is present.
The inductive example is certain only if those five are in fact the entire class. An incomplete list makes the generalization incomplete.