What is an ERC-20 token?

Ethereum request for comment (ERC) serves as a collection of guidelines and proposals that developers can utilize to establish tokens on the Ethereum blockchain. These standards establish a shared framework of rules and recommendations, which enables the developers to create tokens that can seamlessly interact with various projects and applications on the Ethereum network. ERC-20 tokens dictate the creation and management of fungible tokens on the Ethereum blockchain.

Fungible tokens

Fungible tokens are units of digital assets that are identical and interchangeable, meaning each token holds the same value and properties as any other token of the same type. These tokens can represent various real-world or digital assets, such as currencies, commodities, or shares in a project.

ERC-20 interface

The ERC-20 interface is a code representation of the ERC-20 standard in Solidity. It defines the necessary functions and events that a contract must have to meet the ERC-20 requirements. By using this interface, developers can ensure smooth communication between their contracts, wallets, or platforms that support the ERC-20 standard.

interface ERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint256);
    function balanceOf(address _owner) external view returns (uint256);
    function transfer(address _to, uint256 _value) external returns (bool);
    function transferFrom(address _from, address _to, uint256 _value) external returns (bool);
    function approve(address _spender, uint256 _value) external returns (bool);
    function allowance(address _owner, address _spender) external view returns (uint256);
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}

Code for ERC-20 interface

Functions

Following is the description of functionality of the functions of ERC-20.

name(): Retrieves the name of the token.
symbol(): Retrieves the symbol of the token. Symbol of a token is a shorthand identifier typically used in exchanges or user interfaces.
decimals(): Retrieves the number of decimal places used by the token.
totalSupply(): Retrieves the total supply of the token. Total supply indicates the maximum number of tokens that can ever exist.
balanceOf(address _owner): Retrieves the token balance of a specific address. Balance indicates the number of tokens owned by an address.
transfer(address _to, uint256 _value): Transfers a specific amount of tokens from the caller’s account to the specified address. transfer function updates the token balances and triggers the Transfer event.
transferFrom(address _from, address _to, uint256 _value): Transfers tokens from one address to a specified address with proper authorization. transferFrom allows contracts or third parties to transfer tokens on the behalf of an owner.
approve(address _spender, uint256 _value): Grants approval to a specific address to withdraw a specified amount of tokens from the caller’s account. This enables controlled token transfers.
allowance(address _owner, address _spender): Retrieves the amount of tokens that an address is allowed to withdraw from an account, as set by the approve function.

Events:

Following is the description of the events of ERC-20.

Transfer(address indexed _from, address indexed _to, uint256 _value): Triggered when tokens are transferred between addresses.
Approval(address indexed _owner, address indexed _spender, uint256 _value): Triggered when approval is granted for a spender to withdraw tokens.

Use cases of ERC-1155 tokens

ERC-20 tokens have various uses within the Ethereum ecosystem. Here are some examples.

Cryptocurrencies: Many cryptocurrencies are ERC-20 tokens, like Tether (USDT), which provide stability and serve as a medium of exchange in decentralized applications and exchanges.
Initial coin offerings (ICOs): The ERC-20 standard is commonly used for ICOs, where startups raise funds by issuing tokens to investors. This standard ensures a secure and convenient token creation and distribution process.
Decentralized finance (DeFi): ERC-20 tokens play a crucial role in the expanding DeFi sector. They are used as assets for lending and borrowing platforms, provide liquidity on decentralized exchanges (DEXs), serve as governance tokens for DAOs, and enable yield farming in various DeFi protocols.
Loyalty programs: Businesses use ERC-20 tokens as rewards in loyalty programs. These tokens can be redeemed for discounts, special offers, or exclusive access, enhancing customer engagement and retention.
Tokenized securities: Traditional securities, such as stocks and bonds, can be tokenized as ERC-20 tokens. This enables increased liquidity, fractional ownership, and faster transfer of ownership, reducing intermediaries and associated costs.

Conclusion

ERC-20 tokens are a standardized set of rules and recommendations that enable developers to create and manage fungible tokens on the Ethereum blockchain. These tokens represent digital assets and can be easily exchanged with other tokens of the same type. The ERC-20 interface provides a code representation of the ERC-20 standard. ERC-20 tokens have become integral to the Ethereum ecosystem and have revolutionized how digital assets are created, managed, and exchanged.

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