What Is Bitcoin Mining? Consensus, Blocks, and Rewards

The definition, in the protocol’s words

Mining is a distributed consensus system that is used to confirm pending transactions by including them in the blockchain ^[1]. That sentence is the protocol’s own, and every section below unpacks a word of it. Distributed. Consensus. Confirm. Pending. Included.

Older copy on this page described miners solving complex mathematical problems. The phrase is common and it misleads. There is no problem being solved for its own sake. There is a lottery being entered, and the lottery is the security. The protocol’s own framing: the lottery makes it difficult for any single participant to keep adding new blocks one after another ^[1]. This rewrite keeps the protocol’s words and retires the vague ones.

What a miner actually does

A miner does two things in a cycle. First, it assembles a candidate block from valid pending payments. Invalid payments are rejected at this step. Second, it works on the candidate, competing for the right to append it. When a miner wins, its block goes out to the network. Other participants check it. The check is cheap even though the competition was expensive. That asymmetry is the design.

Confirmation is what a payment gains. A payment inside the newest block counts as confirmed once. The protocol’s walkthrough notes a payment usually receives its first confirmation within about ten to sixty minutes ^[1]. Each later block on top adds one more. The older a payment is, the more work would be needed to undo it.

The reward, two streams

The winner of each block is paid from two streams. The first stream is the subsidy: newly issued coins. That subsidy halves every 210,000 blocks, and the fourth halving, in April 2024, brought it to 3.125 coins per block ^[2]. The second stream is the transaction fees inside the block, paid by the transactors themselves ^[2].

The two streams behave differently. The subsidy follows the protocol’s fixed calendar. The fees follow demand for block space. The subsidy trends toward zero over the very long run by design. The fee stream has no schedule. Both are facts about the payment that secures the network, and neither is a forecast.

Why depth is the security

Undoing a payment means redoing its block and every block after it. That is the practical meaning of the blockchain’s structure. Each block carries the work of all blocks above it. A one-block payment can be undone by out-competing one round. A six-block-old payment requires out-competing six rounds of the entire network’s effort. The lottery framing from the protocol’s walkthrough is the same point stated forward ^[1]. One participant keeping the winning streak is what the design prices out. Depth is why the confirmed count of a payment, not the broadcast of it, is what people wait for.

What mining is not

Mining is not a metaphor. It is a payment model that secures the network. Mining is also not a savings product for readers. What an individual earns, if anything, depends on hardware, electricity costs, and participation choices that vary by place and moment. This page states the mechanism. It states no earning claim, and it recommends no hardware. The mine page takes up the practical question in the same terms.

The cap and the count

The supply cap is the FAQ’s own sentence: only 21 million bitcoins will ever be created ^[2]. The count on 12 September 2026 read 20,083,115 coins in circulation, per an on-chain provider’s public supply endpoint ^[3].

One correction rides here, and it is the kind this library exists for. Older copy on this page said over 18 million coins were in circulation. That was true when it was written. It was years stale when read. The replacement is not a new round number. It is a dated read from a named endpoint, so the next reader can tell exactly how fresh the figure is ^[3].

The difficulty rule

More participants make the competition harder. The protocol retargets the difficulty of the work as mining power joins or leaves, keeping block production near its intended pace ^[1]. The rule is automatic. No operator adjusts it. The ten-minute average block cadence is a property the protocol defends, not a statistic it hopes for. The hardware evolution page covers what miners actually run today and how that changed over eras.

The energy question, attributed

Bitcoin’s energy consumption has been estimated, in work this page does not re-derive, as comparable to entire countries, and the environmental impact is a concern for some. Both halves stay attributed. The estimate is somebody’s estimate. The concern is somebody’s concern. This site banks no energy figure with a primary source, so it prints none, and a page that printed one anyway would be dressing a guess as a fact.

Where this page sits

This page is the family’s explainer. The mining overview holds the schedule and the supply count. The mine page takes the direct question, what it takes to mine now. The bitcoin hub is the family’s home root, and what is bitcoin holds the network basics this explainer builds on.