Bitcoin Learning Center
One place to learn Bitcoin.
Nodes
Bitcoin nodes independently verify blocks and transactions against Bitcoin’s consensus rules. When someone broadcasts a transaction, nodes check it and relay it across the network. When a new block is accepted, nodes update their copies of the blockchain and share the most recent version with one another, keeping the network synchronized without a central authority. The globe below represents these connected, independent participants.
Private Keys
Private keys are the secret credentials that prove control of bitcoin. A wallet uses them to authorize transactions without revealing them to the network. Anyone who has your private keys can spend the bitcoin they control, so they should never be shared and should be backed up securely. Self-custody means keeping that authority in your own hands.
Miners
Bitcoin miners use proof of work to compete for the right to add new blocks to the blockchain. They repeatedly calculate hashes until one finds a result that meets the network’s difficulty target, then broadcast the block for nodes to verify. Home mining lets individuals contribute hash rate, strengthen Bitcoin’s security, and participate with hardware sized for their space, power, and goals.