In blockchain terminology, a token is a digital asset created and managed by a smart contract on an existing blockchain. Unlike native coins (ETH, BTC) that are integral to their blockchain's consensus mechanism, tokens are programmable assets that can represent virtually anything: currency, governance rights, ownership stakes, access credentials, or unique digital items.
The token ecosystem has grown to encompass thousands of assets with a combined market capitalization in the hundreds of billions. Understanding the taxonomy of tokens is essential for evaluating DeFi protocols, assessing risk, and navigating the digital asset landscape.
Coins vs Tokens
The distinction between coins and tokens is frequently misunderstood. A coin is the native asset of a blockchain protocol, used to pay transaction fees and reward validators. ETH on Ethereum, SOL on Solana, and BTC on Bitcoin are all coins. They exist at the protocol level.
A token, by contrast, is created by a smart contract deployed on top of an existing blockchain. USDC, UNI, and LINK are all tokens on Ethereum. They do not have their own blockchain; they inherit the security and infrastructure of their host chain.
| Property | Coin | Token |
|---|---|---|
| Blockchain | Has its own | Lives on another blockchain |
| Purpose | Pay gas, secure network | Application-specific utility |
| Creation | Genesis block or mining/staking | Smart contract deployment |
| Transfer | Native protocol transaction | Smart contract function call |
| Examples | ETH, BTC, SOL | USDC, UNI, LINK, AAVE |
Fungible vs Non-Fungible Tokens
Fungible tokens are interchangeable. One USDC is identical to any other USDC, just as one dollar bill is equivalent to another. Fungible tokens are divisible and their units are indistinguishable from one another. They follow the ERC-20 standard on Ethereum.
Non-fungible tokens (NFTs) are unique. Each token has a distinct identifier and can carry unique metadata. A CryptoPunk is not interchangeable with a Bored Ape because they represent different assets with different attributes. NFTs follow the ERC-721 standard.
A third category, semi-fungible tokens, combines both properties. Under the ERC-1155 standard, a token ID can represent a class of fungible items (e.g., 1,000 identical swords in a game) while each class remains distinct from other classes.
Token Standards Overview
Token standards are interface specifications that ensure interoperability across wallets, exchanges, and applications. The most important standards on Ethereum are:
- ERC-20: The fungible token standard. Defines
transfer,approve,transferFrom,balanceOf, andtotalSupplyfunctions. Used by USDC, DAI, UNI, LINK, and thousands of other tokens. - ERC-721: The non-fungible token standard. Each token has a unique
tokenIdand supports metadata viatokenURI. Used by NFT collections, domain names (ENS), and position tokens (Uniswap V3 LP positions). - ERC-1155: The multi-token standard. A single contract can manage both fungible and non-fungible tokens, reducing deployment costs. Popular in gaming.
- ERC-4626: The tokenized vault standard. Standardizes yield-bearing vaults, enabling composability across lending protocols, yield aggregators, and staking derivatives.
Types of Tokens by Function
Utility Tokens
Utility tokens provide access to a specific product or service within a protocol. LINK is used to pay Chainlink oracle operators. FIL pays for decentralized storage on Filecoin. The value of a utility token is theoretically tied to demand for the underlying service.
Governance Tokens
Governance tokens grant voting rights over protocol decisions. UNI holders vote on Uniswap fee structures and treasury allocations. AAVE holders govern the Aave lending protocol's risk parameters. Governance tokens effectively make protocol users partial owners.
Security Tokens
Security tokens represent ownership in real-world assets or investment contracts. They are subject to securities regulation and must comply with frameworks like Regulation D or Regulation S in the United States. Examples include tokenized equities, real estate shares, and revenue-sharing agreements.
Stablecoins
Stablecoins are tokens designed to maintain a stable value relative to a reference asset, typically the US dollar. They are the backbone of DeFi, serving as the primary medium of exchange, unit of account, and store of value within the ecosystem.
Stablecoin Mechanisms
- Fiat-backed (USDC, USDT): Each token is redeemable for $1 held in reserve by a custodian. Circle holds reserves for USDC in cash and short-term US Treasuries. Tether's USDT reserves include a mix of cash, Treasuries, and other assets.
- Crypto-collateralized (DAI): Users deposit crypto assets (ETH, WBTC) into MakerDAO vaults as collateral and mint DAI against them. Loans are over-collateralized (typically 150%+) to absorb price volatility. If collateral value drops below the liquidation ratio, the position is liquidated.
- Algorithmic: These attempt to maintain peg through algorithmic supply adjustments without full collateral backing. The collapse of UST/LUNA in May 2022, which erased over $40 billion in value, demonstrated the fragility of this model.
Wrapped Tokens
Wrapped tokens are representations of assets from one blockchain on another. WBTC (Wrapped Bitcoin) is an ERC-20 token on Ethereum backed 1:1 by BTC held in custody by BitGo. WETH (Wrapped Ether) wraps native ETH into an ERC-20 compliant token, which is necessary because ETH itself predates the ERC-20 standard and does not implement its interface.
Wrapping enables cross-chain composability. Bitcoin, which has no native smart contract capability comparable to Ethereum, can participate in DeFi through WBTC. Wrapped tokens introduce custodial trust assumptions, however, since users must trust the custodian to maintain the 1:1 backing.
How Tokens Are Created and Managed
Creating a token involves deploying a smart contract that implements the relevant standard's interface. For an ERC-20 token, this means implementing the six required functions (totalSupply, balanceOf, transfer, approve, transferFrom, allowance) plus optional metadata functions (name, symbol, decimals).
Token supply can be fixed (minted entirely at deployment, like UNI's 1 billion tokens) or dynamic (minted and burned by protocol logic, like DAI). Some tokens implement deflationary mechanisms, burning a portion of tokens on each transfer or through periodic buyback-and-burn programs.
Token distribution typically occurs through a combination of public sales, airdrops to early users, vesting schedules for team and investors, and ongoing emissions to liquidity providers or stakers. The distribution schedule and vesting terms are critical factors in evaluating a token's supply dynamics and potential price impact.
Key Takeaway
Tokens are programmable digital assets that represent value, access rights, and governance power within blockchain ecosystems. Understanding the distinctions between token types, their underlying mechanisms (especially stablecoins), and the standards they implement is fundamental to evaluating DeFi protocols and managing digital asset portfolios.