# ERC 20 ERC 20 Standard // **ERC20 Standard** || **ERC-20** 1. A set of standards based on the [[Ethereum (blockchain)]] blockchain. ERC20 allows anybody to create a [[Token(s)|token]] built on top of Ethereum’s [[[Blockchain|blockchain]]]. It is the basis of the [[Initial Coin Offering (ICO)]] craze and the advent of new “[[Altcoin(s)|altcoins]]”. 3. A technical standard used on the [[Ethereum (blockchain)]] Blockchain. [[Ethereum Request for Comments (ERC)]] stands for Ethereum Request for Comments. '20' is the unique proposal ID number. 5. The standard to which each [[Ethereum (blockchain)|Ethereum]] token complies. It defines the way that each token behaves so that transactions are predictable. Other [[Crypto (cryptocurrency)|cryptocurrencies]] also use the ERC-20 standard, piggybacking on the [[Ethereum (blockchain)]] network in the process. 7. ERC 20 is the most popular token standard and most [[Initial Coin Offering (ICO)]] that have issued their tokens on the Ethereum platform have used it. If you are an Ethereum developer, you can code your smart contracts assured with the knowledge that it can easily interact with ERC 20 [[Token(s)|tokens]]. Just like the [[Ethereum (blockchain)]] developers needn’t know anything more about that token, wallet developers can also breathe easy! They don’t need to do any custom development or integration steps to ensure the token works with their wallet app. It’s a fungible token standard. This means that two coins of any token built on it have the same value at a given point in time. Take the example of LockChain, the decentralized 0%-commission travel marketplace. Their LOC token follows ERC 20, and 1 LOC token has exactly the same value as another LOC token at a certain point in time. 9. ERC-20 is a type of token standard specifically for the [[Ethereum (blockchain)]] blockchain, which ensures the tokens perform in a predictable way by defining a common list of rules for all Ethereum tokens to follow. This allows the [[Token(s)|tokens]] to be easily exchangeable and able to work immediately with [[Decentralized Applications (dApp)|decentralized applications]] that also use the ERC-20 standard. Most tokens released through [[Initial Coin Offering (ICO)]] are compliant with the ERC-20 standard. Used on [[Ethereum (blockchain)]] blockchain platform, along with [[Ether (ETH)|Ether]] token. On of many [[Ethereum Request for Comments (ERC)]]. 6. “[[Ethereum Request for Comments (ERC)|Ethereum Request for Comments]] 20,” more commonly known as ERC-20, is a technical standard used to implement smart contracts that create the API for tokens on the Ethereum [[blockchain]]. Adhering to this standard allows tokens on [[Ethereum (blockchain)]] to be re-used by other applications: from wallets to [[Decentralized Exchange (DEX)|decentralized exchanges]]. [[Token(s)|Tokens]] created under this standard are known as ERC-20 tokens. As of September 16, 2019, a total of 213,732 ERC-20 compliant tokens were found on Ethereum network. 7. What are ERC-20 tokens? ERC-20 tokens are [[Token(s)|tokens]] designed and used solely on the [[Ethereum (blockchain)]] platform and follow the ERC-20 token standard. [[Smart Contract|Smart contracts]] are responsible for creating the tokens, handling transactions, and keeping track of the balances. There are six mandatory functions that an ERC-20 token smart contract must implement, including: - Creating a method that defines the total supply of tokens, which will allow the smart contract to refuse new tokens once the cap is met. - Creating a method to show the balance of tokens in each respective [[address]]. - Creating a transfer method to take tokens from the total supply and giving them to a user. - Creating a transfer method to allow users to transfer tokens between themselves. - Creating a method to approve [[Transaction(s)|transactions]] from user to user, ensuring that the total supply has a greater balance than or equal to the amount being sent (if sending tokens from a non-personal balance). - Creating a method to approve transactions from user to user, ensuring that the user has a balance greater than or equal to the amount being sent. Optionally, the ERC-20 standard also allow developers to give their tokens a name, symbol, and determine how dividable their token is by specifying the number of decimals that the token can support.