What is the difference between Bitcoin and other cryptocurrencies?

Bitcoin, created in 2009, was the first cryptocurrency and operates as a decentralized digital currency using blockchain technology. Other cryptocurrencies (altcoins) differ in several ways: Bitcoin has a fixed supply of 21 million coins, making it scarce, while many altcoins have unlimited supplies. Bitcoin focuses solely on peer-to-peer transactions, whereas Ethereum and others offer smart contracts—self-executing agreements that enable applications like DeFi and NFTs. Bitcoin uses Proof-of-Work mining for security, while alternatives use different methods like Proof-of-Stake. Bitcoin has the largest market capitalization (around $1 trillion) and longest track record, offering greater stability than newer cryptocurrencies. Different altcoins serve specific purposes: Ethereum for decentralized apps, Ripple for payments, or Dogecoin as a meme coin. Bitcoin's dominance and established use case make it the most recognized and typically least volatile cryptocurrency.