Glossary

The words of bitcoin in plain English, from address to testnet.

The words you will hear

Thirteen terms, in alphabetical order, explained in one line each.

Address

Where a payment is sent. Wallets make a new one for every payment you receive.

Block

A batch of payments added to the record, about every ten minutes.

Confirmation

Each block added after yours. More confirmations make a payment harder to undo.

Fee rate

What you offer miners per unit of space your payment takes, shown in sats per vbyte.

Halving

The cut in the new-coin reward every 210,000 blocks, roughly every four years.

Mempool

The waiting room of payments not yet in a block.

Mining

Using computers to compete for the right to add the next block.

Node

A computer running bitcoin software that checks every rule for itself.

Private key

The secret that signs payments. Whoever has it controls the coins.

Recovery words

Twelve or twenty-four words that rebuild your keys. Also called a seed phrase.

Sat

The smallest unit: one hundred-millionth of a bitcoin.

Self-custody

Holding your own keys instead of leaving coins with a company.

Testnet

A practice network whose coins have no value, used for learning and testing.