Short answers, pulled from the story.
Athenian democracy developed around the 6th century BC through a series of reforms. Solon laid early foundations in 594 BC, Cleisthenes restructured the citizen body in 508-507 BC, and Ephialtes curtailed the powers of the Areopagus in 462 BC. Pericles was the longest-lasting democratic leader.
The word dēmokratia combines dêmos, meaning "people" or "towns", and krátos, meaning "force" or "power", and thus literally means "people power". The earlier word used for the concept was isonomia, also attested in Herodotus.
Only adult male Athenian citizens who had completed military training as ephebes could vote. This excluded women, slaves, freed slaves, children, and metics (resident foreigners). Adult male citizens probably made up no more than 30 percent of the total adult population.
Athenian courts used juries selected by lot from an annual pool of 6,000 citizens. The minimum jury size was 200 for private suits and 501 for public suits; the largest recorded juries reached 6,000. Cases had to be completed by sundown, speeches were timed by a water clock, and no appeal was possible.
Democracy was suppressed by the Macedonians in 322 BC. It had previously been briefly interrupted by oligarchic coups in 411 and 404 BC, and Philip II of Macedon had conquered Athens in 338 BC. A nominal restoration occurred in 307 BC, but Athens had by then become, by accounts of the period, politically impotent.
Ancient critics included Thucydides, Plato, Aristotle, Aristophanes, and the writer known as the Old Oligarch. Thucydides argued that common people were too credulous to rule justly; Plato and Aristotle saw democracy as the poor tyrannizing the rich. The execution of Socrates in 399 BC is frequently cited as the most notorious example of democratic injustice.