They are the methods of logic. Deductive method is used in philosophical thought, while the inductive method is the basis of all scientific enquiries. In spite of their difference, the two methods are interdependent Induction means to collect facts or data and to generalise them or draw inferences from them, which becomes a principle or law.
Deduction is the opposite method: it is to draw conclusions from a principle or law. Inductive method is empirical and logical, while the deductive method is purely logical. “It is better to differentiate between the two by saying that we employ inductive methods when we seek to establish truth by observing reality, and that we employ deductive methods when our concern is primarily with the implications of given premises”
Political scientists employ both inductive and deductive methods in the observation and study of politics and State and its various institutions. These two methods are parts of the analytical as well as of the empirical methods.