Political philosophy is the study of politics, liberty, justice, property, and rights. Also the law, and its enforcement (a legal code) by authority. It concerns not the details, but the basic principles, reasons and arguments.
Topics studied include the purpose of government, what rights and freedoms it should protect, what form it should take, and what the law is. Also, what duties citizens owe to a legitimate government, and when it may be legitimately overthrown, if ever.