Proof of work (PoW) and the coin/token distinction answer two different questions. PoW describes the mechanism used in blockchains such as Bitcoin to support consensus and block production. The coin/token distinction describes an asset’s relationship to a blockchain.
This article uses coin for a blockchain’s native asset and token for an asset issued through a smart contract or a separate protocol built on an existing blockchain. These are common conventions, although terminology varies across the industry.
Bitcoin (BTC) is a native coin on a PoW blockchain. Ether (ETH) is a native coin on a proof-of-stake blockchain. Tokens can exist on either type of chain. The key distinction is therefore not simply whether an asset is “mined” or “minted,” but whether it belongs to the blockchain’s base protocol or is issued on top of it.
What Proof of Work Actually Describes
In Bitcoin, miners repeatedly hash a candidate block header, searching for a hash whose numerical value is less than or equal to the network’s current target. Finding a qualifying hash requires computational work and is probabilistic. Nodes independently validate blocks against Bitcoin’s consensus rules, and accumulated proof of work helps determine which valid chain they follow.
This process makes rewriting confirmed transaction history costly. A valid block includes a coinbase transaction, through which the miner can claim the block subsidy and transaction fees from the included transactions. The Bitcoin Developer Guide explains these rules.
PoW describes how work contributes to block production and blockchain security. It does not, by itself, classify every asset represented on that blockchain.
What Makes an Asset a Native Coin?
A native coin is the protocol-level asset of its blockchain. Its balances and issuance follow the chain’s base rules, and it is typically used to pay base-layer transaction fees. Depending on the blockchain, issuance may involve mining, staking rewards, an initial allocation, or another protocol-defined mechanism.
Bitcoin illustrates this distinction. At the fourth halving, at block height 840,000 on April 20, 2024, its block subsidy fell to 3.125 BTC. The subsidy halves every 210,000 blocks under Bitcoin’s issuance schedule. Transaction fees are separate from the subsidy and vary from block to block. Both are denominated in BTC and can be claimed through the coinbase transaction. See Bitcoin.org’s halving overview.
Being a native coin does not determine the consensus mechanism. ETH remains Ethereum’s native coin even though Ethereum Mainnet completed its transition from proof of work to proof of stake on September 15, 2022. ETH is used to pay Ethereum gas fees and is staked to help secure the network. It is no longer issued through Ethereum Mainnet PoW mining. See Ethereum’s explanation of the Merge.
What Makes an Asset a Token?
A token is issued on an existing blockchain through a smart contract or an additional protocol. Its supply and transfer rules are defined at that level, rather than as the chain’s native currency rules.
On Ethereum, ERC-20 defines a common interface for fungible tokens. Contracts expose balances, total supply, and functions such as transfer, approve, and transferFrom, allowing wallets and applications to interact with them consistently. Ethereum nodes execute and validate these contract interactions under the network’s rules. See the ERC-20 token standard.
Ethereum network fees are paid in ETH, including when a transaction transfers an ERC-20 token. A service can sponsor that payment for the user, so the token holder does not always need to pay ETH directly. The network’s fee asset nevertheless remains ETH. See Ethereum’s explanations of gas fees and gas sponsorship.
Minting and Mining Are Different Concepts
Minting means creating new token units under a token’s rules, such as through a contract function that increases supply. It does not necessarily involve mining.
Some token protocols require proof of work for issuance. That work is separate from the host blockchain’s consensus: earning newly issued tokens does not mean the participant is producing the host chain’s blocks. A token with PoW-based issuance therefore remains a token under the distinction used here.
Can a Token Exist on a Proof-of-Work Blockchain?
Yes. A PoW blockchain can host tokens without those tokens becoming its native coin.
Bitcoin’s Runes protocol is one example. It allows Bitcoin transactions to etch, mint, and transfer fungible tokens using messages called runestones. Software that understands Runes interprets these messages and tracks rune balances associated with Bitcoin transaction outputs. See the Ordinal Theory Handbook.
A rune is not BTC, and Bitcoin does not issue runes as part of its block subsidy. Bitcoin’s consensus rules validate the underlying Bitcoin transactions; Runes-aware software applies the additional rules that determine rune balances and transfers.
Bitcoin miners continue to hash block headers and earn BTC-denominated block rewards. When they include a transaction carrying Runes data, they can collect its transaction fee in BTC. They do not receive a separate rune-denominated protocol reward merely for including that transaction.
Token-related activity can contribute transaction fees, but it does not change Bitcoin’s block subsidy or mining algorithm.
Practical Differences for Miners, Users, and Developers
| Question | PoW native coin, such as BTC | Token, such as an ERC-20 token or a rune |
|---|---|---|
| How does it relate to the blockchain? | It is the native asset of a blockchain that uses PoW. | It is issued through a contract or an additional protocol on an existing blockchain. |
| What secures transaction ordering and history? | The blockchain’s PoW-based consensus. | The host blockchain’s consensus. |
| What determines asset balances and valid transfers? | The blockchain’s native asset rules. | Contract rules executed by the host chain, or additional protocol rules interpreted by compatible software. |
| How is new supply created? | According to the base protocol. For Bitcoin, newly issued BTC is claimed through the coinbase transaction. | According to the token’s rules, which may allow an initial allocation, later minting, or PoW-based issuance. |
| Does mining issue the asset? | For Bitcoin, miners can claim the block subsidy when producing a valid block accepted into the chain. | Usually not through host-chain mining. Some tokens use a separate PoW issuance mechanism. |
| What pays base-layer transaction fees? | Typically the native coin; Bitcoin fees are paid in BTC. | Typically the host chain’s native coin; Ethereum fees are paid in ETH and Bitcoin fees in BTC. |
| Does the consensus mechanism alone determine coin or token status? | No. Native coins can exist on PoW or non-PoW blockchains. | No. Tokens can exist on PoW or non-PoW blockchains. |
For Bitcoin miners and pool operators, the practical point is straightforward: the block subsidy and on-chain transaction fees are denominated in BTC. Carrying token-related transactions does not change those protocol rewards. The token’s own issuance rules are a separate question.
FAQ
Is Every PoW Coin Also a Native Coin?
Under the terminology used here, yes. A “PoW coin” means the native asset of a blockchain secured through proof of work, such as BTC on Bitcoin. A token that uses PoW for issuance remains a token because it is issued on an existing blockchain.
Is Ethereum’s ETH a PoW Coin?
No. ETH is Ethereum’s native coin, but Ethereum Mainnet moved to proof of stake on September 15, 2022. Ethereum Mainnet no longer uses PoW mining.
Are All Tokens Smart-Contract Tokens?
No. ERC-20 tokens use smart contracts, while protocols such as Runes define token rules through Bitcoin transaction data interpreted by compatible software.
Does Hosting a Token on a PoW Blockchain Mean Miners Are Mining That Token?
No. Including transactions involving a token does not itself issue that token to miners. For example, Bitcoin miners can collect BTC transaction fees from transactions carrying Runes data; the Runes issuance rules remain separate.
Does Minting a Token Mean the Same Thing as PoW Mining?
No. Minting creates token units, while PoW mining involves computational work. Some token protocols connect the two by requiring proof of work to mint tokens, but that does not make the token a native coin or make its issuance work part of the host chain’s consensus.