What is the difference between a Bitcoin and an altcoin?

A Bitcoin is the original cryptocurrency, created in 2009, and is still the most widely used and well-known digital currency today. An altcoin is an alternative cryptocurrency that was created after Bitcoin, and uses a different protocol or blockchain, with different features and functions. Altcoins are typically less popular than Bitcoin and trade at smaller volumes, and may be more susceptible to volatility in the markets.