Self-government is the ability of a group of people to make their own decisions and control their own affairs without someone else being in charge of them. When the American colonists fought for independence from Britain, they were fighting for self-government: the right to create their own laws and choose their own leaders rather than having a king across the ocean make those decisions.

The concept works at different scales. A country practices self-government when its citizens elect representatives and participate in democracy. A classroom might have self-government when students create their own rules for group work and hold each other accountable. Even a club needs self-government to decide its activities and solve its problems without a teacher always stepping in.

Self-government requires certain qualities from the people practicing it. They need to think beyond their own immediate wants, consider what's fair for everyone, and follow through on their responsibilities. A group with self-government must make decisions together, enforce their own rules, and live with the consequences of their choices.

The phrase captures something important: the same people who are governed (controlled by rules and laws) are also the ones doing the governing (making and enforcing those rules). It's the difference between being told what to do and having a real voice in the decisions that affect your life.