One-sentence answer
Miners assemble candidate blocks and vary data until the meets the difficulty target, attaching a real and verifiable cost to proposing history.AT A GLANCE · EXPAND A STEP
01Build a candidate
Select valid records and include the previous block hash.
02Try repeatedly
Change the nonce and other data; hash the block header.
03Broadcast a result
Nodes check difficulty, transactions, and other rules before acceptance.
This diagram explains relationships, not the complete protocol implementation.
It is not solving a useful math puzzle
Miners vary a and other data, the header, and look for a result below the current target. There is no shortcut to predict a winning attempt, while any node can check one quickly.
That asymmetry—hard to produce and easy to verify—is the core of .
Why competition needs a cost
If proposing history were nearly free, an attacker could cheaply manufacture many conflicting versions. makes candidate blocks carry real computation and energy cost.
compare accumulated work among valid chains, not a simple count of blocks or node votes.
Mining and issuance
A valid ’s coinbase transaction can claim the subsidy and fees, so mining is also how new BTC enters circulation according to the rules. Issuance is an incentive, not mining’s entire purpose.
As the subsidy declines, fees are expected to become a larger relative part of miner revenue.
TRY IT YOURSELF
What does mining actually try?
—Not started. Change the text or difficulty and try it.
Finding a result takes attempts; checking it needs one hash. Outcomes depend on the input, not a scripted animation. Higher difficulty needs more attempts on average.
Teaching limits: one SHA-256 over teaching text, not Bitcoin’s full block format or double hashing. Difficulty and speed do not represent real mining.
Open standalone experimentCHECK YOUR UNDERSTANDING
Does a valid proof of work guarantee valid transactions?
A correct answer saves local progress. No account needed.View my learning pathThree things to remember
- ✓Mining repeatedly tries hashes; it is not solving an externally useful equation.
- ✓Work is difficult to produce and easy for nodes to verify.
- ✓Miner revenue can include both subsidy and fees.
A common follow-up
Does a larger nonce make a block safer?
No. A nonce is only one field miners can vary. Security comes from accumulated work on a valid chain, not the nonce value itself.
Primary sources
Primary sources
These links lead to protocol material, developer documentation, or open-source code—not trading services.