Education in ancient Greece had two forms: formal provided by public schools or tutors, and informal without payment. The purpose of education differed between city-states - in Athens it was to produce good citizens, while in Sparta the purpose was to produce a powerful army. Sparta's education system focused on military training for boys from a young age. Key Greek philosophers like Socrates, Plato, and Aristotle influenced the development of modern education through their teachings and writings. Greek contributions included the first democracy in Athens, architecture like the Parthenon, inventions, athletics like the Olympics, and establishment of early schools.