Tokens on the Ethereum network are created and implemented using the ERC-20 technical standard. Fabian Vogelsteller, an Ethereum engineer, made the suggestion in November 2015. The standard outlines a set of guidelines that must be adhered to for a token to operate correctly within the Ethereum ecosystem. As a result, ERC-20 shouldn't be viewed as a program or piece of software. Instead, it might be referred to as a technical standard or guideline. The ERC-20 standard makes it simpler for developers to forecast with greater accuracy how various tokens and applications will interact. Additionally, it specifies how ERC-20 tokens are moved throughout the Ethereum network as well as how their supply and address balances are continually kept track of. In other words, the ERC-20 provides developers with a set of guidelines to adhere to, allowing for smooth operation inside the larger Ethereum ecosystem. ERC-20 tokens are supported by a large number of decentralized applications (DApps) and services, making it simpler for businesses and members of the community to accept and use them on a variety of applications (such as games, decentralized exchanges, cryptocurrency wallets, and so forth). On the Ethereum blockchain, there are many ERC20-compliant tokens in use, each with a different implementation. The tokens can represent a variety of digital assets or trade products (such as coins, vouchers, gold certificates, loyalty points, and IOUs) depending on the strategy utilized. Additionally, voting rights during elections may be tokenized using ERC-20 tokens. The ERC-20 standard dramatically decreased the work necessary to develop and release a digital token, which is likely related to the growing popularity of ICO crowdfunding campaigns and blockchain technology in general. The technical standard is already in use by a number of projects, and in the past two years, the number of ERC-20 token contracts has significantly increased. On the Ethereum network, there were about 5,500 ERC-20 smart contracts as of the middle of 2017. This figure was over 40,000 in early 2018 and has since increased to over 160,000. Despite the fact that most tokens on the Ethereum network adhere to the ERC-20 standard, some do not. For instance, Ether (ETH) was developed prior to the standard and is not yet compliant. As a result, the so-called Wrapped Ether (WETH), an ERC-20 token with a 1:1 representation of Ether (1 WETH = 1 ETH), was developed. On decentralized exchanges, WETH users can exchange their ETH for other ERC-20 tokens. Technically speaking, the ERC-20 standard outlines six functions that preserve various features and functionality of digital tokens based on Ethereum. These features cover how tokens are moved between addresses as well as some crucial information about the token smart contract, such as its symbol, name, and supply.