ERC-20 stands for Ethereum Request for Comments 20. It is a standard for creating digital tokens on the Ethereum network. A token that follows this standard is called an ERC-20 token.

ERC-20 tokens are fungible. This means each unit of the token has the same value as any other unit of that same token. For example, one Ethereum (ETH) has the same value as any other ETH, and one Shiba Inu (SHIB) has the same value as any other SHIB. Money works the same way: one US dollar has the same value as any other US dollar, no matter where you spend it.

Because all ERC-20 tokens follow the same standard, developers can build apps and services that work with any ERC-20 token without writing separate code for each one. This is why so many different tokens on Ethereum use the ERC-20 standard.