How does a pegged exchange rate work?

How does a pegged exchange rate function exactly? Could you elaborate on the mechanisms involved in maintaining such a stable rate between two currencies? Does it rely on government intervention or market forces? What are the benefits and drawbacks of using a pegged exchange rate system? Is it easier to predict and manage fluctuations in exchange rates with a pegged system compared to a floating exchange rate? Lastly, how does a country go about changing its exchange rate regime from floating to pegged, or vice versa?