An ERC20 token is a type of token that follows the ERC20 standard for Ethereum which enables the creation of new tokens.
ERC20 is a standard used for creating and issuing smart contract-based tokens on the Ethereum blockchain. It provides a list of rules that all Ethereum-based tokens must follow, including how the tokens can be transferred, how transactions are approved, how users can access data about a token, and the total supply of tokens. This standardization allows different ERC20 tokens to interact with each other within a shared ecosystem (such as a single cryptocurrency exchange), which simplifies the creation of new tokens. Many of the tokens used in Initial Coin Offerings (ICOs) are ERC20 tokens.
Tokens such as USD Coin (USDC), Uniswap (UNI), and Chainlink (LINK) are examples of ERC20 tokens.