What were city states of Athens called?

This is a very complex matter, but I'll try to give you a brief answer. Ancient Greek Cities-States where a very small town or city with its around territory part of them. Greeks would speak the same language (in many dialects), have same religion, customs and bloodline but were very topicists and individual. Do not think big, like a modern Athens or Paris or London. Think that all Greece is almost the same as the whole state of New York. Now think that Athens is 1/3 of NYC. You get the picture. Imagine that Bronx, Kings, New York, Queens, Richmond were separate and individual complete independent countries as the Greek cities states of same NY culture, but all waging war to each other and all together against Pennsylvania or Massachusetts. In order to achieve this they would form a Koinon (pron. kéénon -> "commonwealth") a confederation or alliance for military reasons. e.g the Koinon of NY so all would attack the city state of Boston or sometimes go bigger as the Koinon of North-East (like tenths of cities from NY, Pennsylvania, New Jersey, Massachusetts) and go to war against the Koinon of South East (like cities from Florida, Alabama, Georgia). Then the strongest or most influential culturally city would prevail and be in charge e.g the Delian League with Athensor Peloponnesian League with Sparta or the Hellenic League with the Macedonians).

The Greeks, would 95% go to war against each other and not so often against other culture nations. The only notable time in antiquity that they had a Greek Koinon as a whole, was with Alexander, when they conquered almost all known world.

Straight Answer:

Delian League.