Short answers, pulled from the story.
Democracy comes from the Greek words demos, meaning the common people, and kratos, meaning force or might, together meaning rule of the people. The term appeared in the 5th century BC in Greek city-states, notably Classical Athens, in contrast to aristocracy, which meant rule of an elite.
Cleisthenes is referred to as the father of Athenian democracy. Under him, what is generally held as the first example of this kind of government was established in Athens in 508-507 BC.
In a direct democracy, the people have the direct authority to deliberate and decide legislation themselves. In a representative democracy, citizens choose governing officials through elections to govern on their behalf, and it is today the dominant form of democracy.
In 1893, the self-governing colony of New Zealand became the first country in the world to establish active universal suffrage by recognizing women as having the right to vote, except for the short-lived 18th-century Corsican Republic.
According to the V-Dem Democracy indices and The Economist Democracy Index, less than half the world's population lives in a democracy. Freedom House recorded that electoral democracies grew from 40 in 1972 to 123 in 2007.
A 2019 study by Daron Acemoglu and others estimated that countries switching from authoritarian to democratic rule had on average a 20% higher GDP after 25 years. The study examined 122 transitions to democracy occurring between 1960 and 2010, and democracy more consistently results in improved health, education, and economic outcomes.