What Are ERC-20 Tokens? Ethereum's Token Standard Explained

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ERC-20 is the backbone of tokenization on the Ethereum blockchain, enabling seamless interoperability across decentralized applications (dApps) and exchanges. Unlike ERC-721 (NFTs), ERC-20 tokens are fungible—each unit is identical and interchangeable. This standard’s brilliance lies in its smart contract compatibility, making it the go-to framework for creating utility tokens, stablecoins, and governance assets.


Table of Contents

  1. What Is ERC-20?
  2. History of ERC-20
  3. ERC-20 Technical Structure
  4. Key Functions of ERC-20 Tokens
  5. ERC-20 vs. Other Token Standards
  6. Top ERC-20 Token Use Cases
  7. FAQs

What Is ERC-20?

ERC-20 (Ethereum Request for Comment 20) is a technical standard for creating tokens on Ethereum. It defines a set of rules—like a blueprint—ensuring tokens work uniformly across wallets, exchanges, and dApps.

Why It Matters:

👉 Discover how top DeFi projects leverage ERC-20 tokens


History of ERC-20

Proposed by Fabian Vogelsteller in 2015, ERC-20 solved a critical problem: the lack of token standardization. Before ERC-20, each Ethereum-based token had unique code, causing compatibility issues.

Key Milestones


ERC-20 Technical Structure

ERC-20 tokens must implement these core functions:

FunctionPurpose
totalSupply()Returns the total number of tokens in circulation.
balanceOf()Checks the token balance of a specific wallet address.
transfer()Moves tokens from the sender to another address.
approve()Allows a third party (e.g., an exchange) to spend tokens on your behalf.

Optional Metadata: Token name (e.g., "Chainlink"), symbol (LINK), and decimals (18).


Key Functions of ERC-20 Tokens

1. Transfer Mechanism

2. Balance Tracking

3. Automated Trading


ERC-20 vs. Other Token Standards

StandardTypeUse CaseExample
ERC-20FungiblePayments, DeFiUSDC, LINK
ERC-721Non-FungibleUnique assets (NFTs)CryptoPunks
BRC-20Bitcoin-basedExperimental tokens on BitcoinORDI

Why ERC-20 Dominates:


Top ERC-20 Token Use Cases

  1. Stablecoins: USDT, USDC (pegged to USD).
  2. DeFi Tokens: UNI (Uniswap), COMP (Compound).
  3. Governance: Voting rights in DAOs (e.g., MKR).

👉 Explore ERC-20 tokens on leading exchanges


FAQs

Q1: Are ERC-20 tokens safe?

Yes—if the smart contract is audited. However, scams exist (e.g., fake tokens). Always verify contract addresses.

Q2: Why do ERC-20 transactions need gas fees?

Gas (paid in ETH) compensates miners for processing transactions on Ethereum.

Q3: Can I store ERC-20 tokens in any wallet?

Only Ethereum-compatible wallets (e.g., MetaMask, Trust Wallet).

Q4: What’s the difference between ERC-20 and ETH?

ETH is Ethereum’s native currency; ERC-20 tokens are assets built on Ethereum.

Q5: How do I buy ERC-20 tokens?

  1. Centralized exchanges (Coinbase, Binance).
  2. Decentralized exchanges (Uniswap).

Q6: Are ERC-20 tokens scalable?

Limited by Ethereum’s network speed. Layer-2 solutions (Polygon) help reduce fees.


Final Thought: ERC-20’s flexibility and adoption make it the gold standard for blockchain tokenization—powering everything from global payments to decentralized governance.