What is an ERC-20 token?
ERC-20 (Ethereum Request for Comments) tokens are tokens that follow a set of standards defined for smart contracts on the Ethereum blockchain. ERC-20 defines the common rules for developers to adhere to when creating Ethereum tokens.
These standards enable smart contracts (tokens) to share a common programming language. For example, to enable the token to define the total supply of tokens, “totalSupply” would be used, instead of “totalNumber” or “totalTokens”. Compliance with the standards avoids confusion and enables the token to interact with wallets, exchanges, and different smart contracts without running into issues due to individual token differences.
The set of functions defined by the ERC-20 standard are:
- totalSupply - get the total token supply
- balanceOf - get the account balance of account address
- transfer - send the amount of tokens
- transferFrom - define where the tokens are transferring from
- approve - allow tokens to be withdrawn from sending address
- allowance - returns the remaining tokens of the address
ERC-20 tokens are displayed on Etherscan as below when a search of the contract address is performed in the search box under “View Tokens” under “Tokens” tab
However, non-ERC-20 compliant tokens are displayed as below when searched.