Introduction: The world of decentralized applications (DApps) and blockchain technology has witnessed significant growth, with various standards emerging to facilitate the creation and management of tokens. In this article, we'll delve into two prominent token standards: ERC-20 and ERC-721, and explore the evolving landscape of Web3 token standards.

ERC-20: The Foundation of Tokenization

Overview:

ERC-20, or Ethereum Request for Comment 20, is a widely adopted standard for fungible tokens on the Ethereum blockchain. Fungible tokens are interchangeable, meaning each unit is identical to every other unit.

Implementation:

Let's examine a simple ERC-20 token contract in Solidity, Ethereum's smart contract language:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract ERC20Token {
    string public name;
    string public symbol;
    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(string memory _name, string memory _symbol, uint256 _totalSupply) {
        name = _name;
        symbol = _symbol;
        totalSupply = _totalSupply;
        balanceOf[msg.sender] = _totalSupply;
    }

    function transfer(address to, uint256 value) external returns (bool) {
        require(balanceOf[msg.sender] >= value, "Insufficient balance");
        balanceOf[msg.sender] -= value;
        balanceOf[to] += value;
        emit Transfer(msg.sender, to, value);
        return true;
    }

    function approve(address spender, uint256 value) external returns (bool) {
        allowance[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) external returns (bool) {
        require(balanceOf[from] >= value, "Insufficient balance");
        require(allowance[from][msg.sender] >= value, "Insufficient allowance");
        balanceOf[from] -= value;
        balanceOf[to] += value;
        allowance[from][msg.sender] -= value;
        emit Transfer(from, to, value);
        return true;
    }
}

This basic ERC-20 contract includes functions for transferring tokens, approving spending, and transferring tokens on behalf of another address.

ERC-721: Non-Fungible Tokens (NFTs)

Overview:

In contrast to ERC-20, ERC-721 tokens are non-fungible, meaning each token is unique and cannot be exchanged on a one-to-one basis with any other token.

Implementation:

Here's a simplified ERC-721 contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract ERC721Token is ERC721, Ownable {
    uint256 public nextTokenId = 1;

    constructor(string memory _name, string memory _symbol) ERC721(_name, _symbol) {}

    function mint(address to) external onlyOwner {
        _safeMint(to, nextTokenId);
        nextTokenId++;
    }
}

This ERC-721 contract inherits from OpenZeppelin's ERC721 and Ownable contracts. It allows the owner to mint unique tokens.

Beyond ERC-20 and ERC-721: Exploring New Standards

ERC-1155: Multi-Token Standard

Developed to address some limitations of ERC-20 and ERC-721, ERC-1155 supports multiple token types within a single contract. It's efficient and flexible, making it suitable for various use cases.

Implementation:

ERC-1155 contracts are more complex, involving the management of multiple balances for different token types. The OpenZeppelin library provides a solid implementation.

ERC-777: Advanced Token Standard

Introducing more features like "hooks" for token transactions, ERC-777 is designed for enhanced functionality and security compared to ERC-20.

Implementation:

Implementing ERC-777 involves additional functions and considerations for token transactions.

Conclusion:

Understanding token standards like ERC-20 and ERC-721 is crucial for anyone navigating the Web3 landscape. As blockchain technology evolves, new standards like ERC-1155 and ERC-777 offer enhanced capabilities, providing developers with a broader toolkit for building decentralized applications.

Remember to stay updated on the latest developments in Web3 token standards, as the landscape is dynamic, and emerging standards may redefine how we tokenize assets and interact with decentralized systems.