BEGINNER PATH / 02

WHAT IS A BLOCKCHAIN?

In Bitcoin, the blockchain is the shared public transaction record that the network uses to agree which bitcoin has already been spent and which can still be spent.

01TRANSACTIONS

People create and broadcast Bitcoin transactions.

02VALIDATION

Network participants check transactions against Bitcoin's rules.

03BLOCK

Miners assemble valid transactions into candidate blocks.

04PROOF OF WORK

A valid proof-of-work allows a new block to be proposed to the network.

05CHAIN

Each block refers to the previous one, creating a chronological history.

WHY BLOCKS LINK / 03

CHANGING OLD HISTORY GETS HARDER.

Bitcoin's proof-of-work links the cost of changing an old block to all of the work that followed it. New blocks therefore add further evidence behind the transaction history already recorded.
PUBLIC

THE RECORD CAN BE CHECKED

Bitcoin's blockchain is not a secret bank database. Transactions and blocks can be independently verified by software following Bitcoin's consensus rules.

ORDER

BLOCKS CREATE HISTORY

Blocks provide a chronological structure so the network can agree which transactions came before others.

CONFIRM

MORE BLOCKS = MORE CONFIRMATIONS

When later blocks are added after the block containing your transaction, its confirmation count increases.

FEES & CONFIRMATIONS →