ERC-20 provides a standard means of exchanging tokens that may interact with smart contracts. Tokens in this context are symbols that may be exchanged for anything else, such as assets, rights, ownerships, access, cryptocurrencies, or anything else that is not really unique. Tokens representing one of these things, coupled with smart contracts, may be traded for tokens representing another using the standard. The terms of a smart contract are predetermined in the code, and the contract itself serves to execute the various parts of a business deal.