ERC

"ERC-20 came about as an attempt to provide a common set of features and interfaces for token contracts in Ethereum, and has proved to be very successful. ERC-20 has many benefits, including allowing wallets to provide token balances for hundreds of different tokens and creating a means for exchanges to list more tokens by providing nothing more than the address of the token’s contract. The benefits of creating a token as ERC-20 compliant is such that very few token contracts today are created any other way (8-2018) new ERC standards are being made however."
Other well known ERC's are ERC223, ERC777, ERC-1155 and ERC-721o