Polis - Though the word "city" is often used as a translation of polis in this SparkNote's summaries and commentaries, there is no exact English equivalent for the Greek city-state. The polis was a relatively small, self-sufficient, and independent region governed by its citizens, the elite class. The workforce consisted of slaves, manual laborers, and women. Aristotle's world was made up of city-states, and his political theories work from the assumption that the polis is the most sensible form of government.
Koinonia - Roughly translatable as "association," koinonia is defined literally as "a sharing in common." This concept is very important to Aristotle's political philosophy and is integral to the nature of the polis: the polis is an association not only in the sense of people living in the same place, but also in the sense of a shared venture in which all citizens take part. Aristotle thus perceives no conflict between individual and state.
Politeia - Aristotle uses this complex word in two different ways: first, it translates quite directly as "constitution;" second, it describes an entity translated here as "constitutional government" (other translations may render it as "polity"). Aristotle considers constitutional government, in which the masses are granted citizenship and govern with everyone's interest in mind, one of the best forms of government. It combines elements of oligarchy and democracy, finding a compromise between the demands of both the rich and the poor.
Kingship - An idealized form of monarchic government in which the king is an exceptional individual who governs with everyone's best interests in mind. Aristotle acknowledges that finding such an outstanding leader is difficult, but prizes the possibility nonetheless.
Oligarchy - Aristotle uses oligarchy, literally "the rule of the few," to refer to a government controlled by a minority consisting of the wealthy. Unlike aristocracy, Aristotle believes, oligarchy is a bad form of government, as the ruling faction governs solely in its own interests, disregarding those of the poor.
Democracy - Aristotle disparages democracy, literally "the rule of the people," as a type of government in which the poor masses have control and use it to serve their own ends. This involves the heavy taxation and exploitation of the rich, among other things. Among forms of majority rule such as democracy, Aristotle prefers politeia, or constitutional government.
Aristocracy - Aristotle highly esteems aristocracy, literally "the rule of the best," and considers it superior to oligarchy because it values everyone's interests. He contrasts aristocracy with oligarchy, democracy, and politeia by pointing out that these forms of government concern themselves only with questions of wealth. Aristocracy, on the other hand, confers benefits on the basis of merit, with the result that those who most deserve to govern do in fact govern.
Tyranny - The rule of an individual interested solely in his own benefit. A perverse form of kingship, tyranny is unpopular and usually overthrown. In Aristotle's opinion, it is the worst type of government.
Demagoguery - The worst type of democracy, in Aristotle's opinion, is mob rule is carried to an extreme. In demagoguery, everyone's voice is equal, and the rule of the majority has greater authority than the law. As a result, the will of the people supersedes law. Invariably, a charismatic leader, or demagogue, takes control and becomes a tyrant. Because he speaks with the voice of the people, and because the voice of the people is sovereign, the demagogue is free to do what he wants.