You open a crypto app and see Bitcoin, Ether, USDC, and Shiba Inu all listed side by side. They all look like "crypto." But two of them are fundamentally different from the other two — and that difference affects how they work, where their value comes from, and what risks they carry. Here's how we think about it.
In Plain English
There are two kinds of assets in crypto:
- Coins are the native currency of their own blockchain. Bitcoin (BTC) exists only on the Bitcoin network. Ether (ETH) exists only on Ethereum. Each of these blockchains literally could not operate without its coin.
- Tokens are created by a smart contract — a program deployed on top of an existing blockchain. USDC, Chainlink (LINK), and Uniswap (UNI) are all tokens. They run on Ethereum, but they are not Ethereum. They pay their gas fees in ETH.
Think of it this way: a coin is the official currency of a country. A token is a store gift card — it only works inside a specific shop, but you still need local currency to ride the bus to get there.
What Makes Something a Coin
A coin is the native asset of its own blockchain. The network was built around it. BTC is native to Bitcoin. ETH is native to Ethereum. SOL is native to Solana. ADA is native to Cardano. AVAX is native to Avalanche.
Coins serve a structural purpose. They pay validators — the nodes that verify and record transactions — and they fund the security incentives that keep the network honest. Without its coin, a blockchain has no way to compensate the people maintaining it.
Importantly, coins are created by the protocol itself. Bitcoin creates new BTC through mining. Ethereum creates new ETH through staking rewards. No third party decides to issue them — they emerge from the rules baked into the network.
This also means a coin can only be the real thing on its own chain. There is only one genuine BTC, and it lives on the Bitcoin blockchain.
What Makes Something a Token
A token has no chain of its own. Instead, someone deploys a smart contract — self-executing code — on an existing blockchain, and that contract defines the token's rules: total supply, how it transfers, who can mint more.
The most common token standard is ERC-20, which defines a shared interface for fungible tokens on Ethereum. ERC-20 was proposed by developer Fabian Vogelsteller in November 2015. Because every ERC-20 token follows the same interface, wallets and exchanges can support thousands of different tokens without custom integration work for each one.
Other blockchains have equivalent standards: BEP-20 on BNB Chain, SPL token on Solana. The idea is the same — a common contract interface that lets the ecosystem interoperate.
Because tokens inherit the security of the underlying chain, a token on Ethereum is protected by Ethereum's validator network. But that protection only goes as far as the contract code. If the contract has a bug or a hidden admin key, the token itself can be exploited — something that doesn't apply to coins in the same way.
Why Tokens Need the Underlying Coin to Move
This is the part that trips up nearly every newcomer.
Sending a token is still a blockchain transaction. That transaction must be processed by validators, who are paid in the chain's native coin. So when you send USDC on Ethereum, you are not paying a fee in USDC — you are paying a gas fee in ETH.
You can hold $1,000 worth of USDC and be completely unable to move it if your ETH balance is zero. The USDC sits there, valid and yours, but the network won't execute the transfer without ETH to cover the fee.
If you only hold tokens on a chain, keep a small reserve of that chain's native coin to cover gas. It doesn't need to be much — but it needs to be something.
Layer 2 networks like Arbitrum and Optimism are built on top of Ethereum and still use ETH for fees, just at dramatically lower amounts. The dependency remains — it's just cheaper.
A full breakdown of how transaction fees work — including why they spike during busy periods — is worth reading once you're comfortable with the coin/token distinction.
Fungible Tokens vs NFTs: Two Flavours of Token
Not all tokens are interchangeable. This gives us the fungible/non-fungible split.
Fungible tokens (ERC-20) are identical to each other. One USDC equals one USDC in every respect. You can swap them freely and neither party gains or loses anything from which specific token they end up with.
Non-fungible tokens (NFTs, typically ERC-721) are unique. Each token has a distinct identifier, and two NFTs from the same collection are not interchangeable — one might represent artwork #42 and another #43. They are different assets.
Both fungible and non-fungible tokens live on the same blockchain and pay gas in the same native coin. The fungible/non-fungible distinction applies to tokens. Coins are always fungible by design — one BTC is always equal to one BTC.
What This Means for You
Understanding the distinction has practical consequences.
Wallets and addresses. A single crypto wallet address can hold both a chain's native coin and any tokens on that chain. Your Ethereum address is the same address for ETH and for every ERC-20 token. They share the same space.
Risk profile. Coins carry network-level risk — if the blockchain fails, the coin fails. Tokens carry an additional layer: smart contract risk. A poorly written or malicious contract can behave unexpectedly, drain funds, or include a back door for the deploying team.
Scam tokens. Anyone can deploy a token with any name — including "Bitcoin" or "Ethereum" — on any chain. A fake "Bitcoin" token on Ethereum is just a contract with that label; it has no connection to the Bitcoin network or its supply. Coins, by contrast, can only be the genuine article on their native chain. Knowing the difference protects you from some common scams.
Valuation logic. A coin's value is tied to demand for block space on its network. More activity on Ethereum means more demand for ETH to pay fees. A token's value depends entirely on the project behind the contract — and that project's success, adoption, and governance.
Cross-chain movement. Assets don't automatically move between chains. Moving ETH to Solana, or a Solana SPL token to Ethereum, requires a bridge — a system that locks assets on one chain and mints equivalent representations on another. Bridges add their own risk and complexity.
Key Takeaways
- A coin is the native asset of its own blockchain; it cannot exist separately from that network.
- A token is created by a smart contract on an existing blockchain and depends on that chain's coin for gas fees.
- ERC-20, BEP-20, and SPL are token standards — common interfaces that let wallets and exchanges handle any compliant token.
- Even if you hold only tokens, you need a small balance of the host chain's native coin to move anything.
- NFTs are a second type of token (non-fungible), meaning each one is unique rather than interchangeable.
- Scam tokens can mimic any name — coins are always authentic on their native chain.
