Map of Attica in Socrates and Plato's time

Depending on the context, Athens may refer to the city of Athens proper, exclusive of its suburbs such as Piraeus, its main harbor, or the larger urbain area including such suburbs as Piraeus, or the whole of Attica, the territory of the "city-state", in which most of its citizens would live and own land, or even the whole of the Athenian empire that spread all through the Mediterranean, grew and shrunk over the years (the same could be said with little variation of all the "city-states" of ancient Greece, such as Sparta, Thebes, Corinth, etc.). Thus, what were called citizens of Athens, were in fact people living all through Attica, not necessarily in the city of Athens itself, though they all had to go there from time to time to accomplish their civic duties.

The organisation of Attica in the time of Socrates and Plato was the result of a reform by Cleisthenes in 508. According to this organisation, all citizens of Attica entitled to participate in the political institutions of Athens were divided in ten "tribes" (phulai in Greek), named after ten eponym heroes chosen by the oracle of Delphi from a list of one hundred names (a monument with the statues of these ten heroes was built on the Agora of Athens and was used to post official publications).
Attica as a whole was divides into three areas : a peripheral zone along the coast (exclusive of the costal area close to Athens), called Paralia ; a central area called Mesogeia ; and a third one including Athens and its vicinity, called Astu, that is, the City area (astu is the common name in Greek for an urban area as opposed to the countryside, agros). Each tribe was made up of sections of each of these three areas, called trittues in Greek, that is, "Thirds". These so-called tritties were further divided into "demes" (dèmoi in Greek, from the same word, dèmos, which also means "people" and is at the root of such words as "democracy"), corresponding in general to the various villages of Attica and districts of Athens.
Each citizen of Athens was called by the name of his deme, as for instance "Socrates from Alopece" or "Callicles from Acharnæ" (see Gorgias, 495d), or else Æschines of Sphettus, etc., and he had to register in the deme of his father to enjoy his political rights as a citizen of Athens. He would stay a member of that deme even if he was no longer living on its territory.

Aside from this "political" organisation, there remained older groupings, such as "families" (genè in Greek) and "phratries" (groups of people supposed to have a common ancestor), that played a mainly religious role in Socrates' and Plato's time.

Only those demes that are in direct relationship with Plato and the dialogues have been located on the above map. Following is a list of demes arraged by tribes and tritties.

Tribe	"Tritty"
	Atsu (the "city")		Mesogeia (inland)	Paralia (costal area)
	Athens proper	Suburbs
Erechtheides (after Erechtheus, king of Athens)		Euonymon Agyle	Cephisia	Lamptræ Anagyrous
Ægeides (after Ægeus, Theseus' father)	Collytus	Ancyle Colonus	Erchia Gargettus Icaria Teithrasus	Halai Araphenides Philædæ
Pandionides (after Pandion, one of two kings of Athens : Erechtheus' father or Ægeus' father)	Cydathenæum	Cytheræoi	Pæania	Myrrhinus Angeleis Prasiæ Probalinthus Steiria
Leontides (after the Attic hero Leos)	Leuconoe Cholleidæ Scambonidæ	Halimus	Eupyrides Cropia Pæonides Hecale	Phrearrhoi Sunium
Acamantides (after Acamas, one of Theseus' sons)		Cerames Cholarges Hermeion	Sphettus Cephale Hagnus Prospaltes	Thoricus
Oeneides (after Oeneus)	Oa	Laciadæ Perithoedæ	Acharnæ	Thria Cothocidæ Phile
Cecropides (after Cecrops, first king of Athens)		Melite Xypete	Phlia Athmonia	Æxone Halai Æsonides
Hippothoontides (after the Attic hero Hippothoon)	Coele	Piræus	Decelea	Eleusis Oenoe (of the west)
Æantides (after Ajax, king of Salamis)		Phaleron	Aphidna	Marathon Oenoe (of the east) Rhamnus
Antiochides (after Antiochus, son of Heracles)		Alopece	Pallene	Anaphlystus Ægilia Amphitrope Ateneis Thoræ