Answer: "A city-state, or polis, was the community structure of ancient Greece. Each city-state was organized with an urban center and the surrounding countryside. Characteristics of the city in a polis were outer walls for protection, as well as a public space that included temples and government buildings."
"The polis was a structure of community amongst the ancient Greek world and it controlled a surrounding territory of land. An individual polis was independent from the other poleis in regards to legal, religious, social, political and judicial institutions and practices."