An ERC20 token is a digital asset or cryptocurrency that is created and managed on the Ethereum blockchain. It follows a set of standard rules and specifications defined by the Ethereum community for tokens to be accepted on the blockchain network. ERC20 tokens are compatible with several wallets and exchanges that support ERC20 tokens, making it easier for developers to create new blockchain-based assets and trade them in a decentralized ecosystem. They are commonly used as a means of payment, investment, and reward in decentralized applications (dApps) built on the Ethereum network.