An altcoin is any cryptocurrency other than Bitcoin, created to offer alternative features such as faster transactions, different consensus mechanisms, or specific use cases.
The main altcoins include Ethereum, Binance Coin, Ripple (XRP), Cardano, Solana, Dogecoin, Polkadot, Avalanche, Litecoin, Tron, Polygon, Chainlink, Stellar, Shiba Inu, and Uniswap.
An altcoin can be created by any individual, developer, or organization with the technical skills to write code, launch a blockchain or fork an existing one, and build the supporting network and community.