Block
A batch of transactions with a timestamp and the hash of the block before it.
Block in more detail
A blockchain is a record of transactions grouped into blocks, where each block is locked to the one before it. That lock is what makes old records so hard to change.
A ledger is a list of transactions: who paid whom, and how much. In Bitcoin, independent computers called full nodes each keep a copy of the ledger and check every transaction and block against the rules. Anyone with a suitable computer and connection can run one.
New transactions are collected into a block. On Bitcoin, a new block is added about every ten minutes on average.
All 128 terms · Checked against the lesson's sources on 8 October 2026.
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