Political science is the systematic study of governments, of the methods by which governments seek to control people, and of the techniques through which people try to influence government. It is a science that attempts to connect the "micro" level of individual lives and actions with the "macro" level of collective circumstances and consequences.
Like the other social sciences, political science focuses on all three basic types of social power: the pen, the purse, and the sword. Unlike the other social sciences, it gives special attention to the power of the sword: wielded collectively in the form of war and threats of war, wielded against individuals—ideally— in the more civilized form of laws.
Every body of knowledge has at least a few basic words that students had better understand in the fullest possible sense. For the physicist, "force" must equal mass times acceleration. Accountants must understand that "assets" are equal to liabilities plus owners' equity (capital) and must be able to classify particular transactions into the proper categories. Music theorists must know the difference between a second inversion and a secondary dominant. Political science is no exception to this general need for fundamental concepts