Blockchain

Last Updated Sep 24, 2026

In One Sentence

A blockchain is a shared digital ledger that records data in cryptographically linked blocks, making past records difficult to alter.

What Is a Blockchain?

A blockchain is a digital ledger maintained across a network of computers. It stores transactions or other data in blocks linked using cryptographic hashes.

How Does It Work?

  1. Participants submit transactions to the network.
  2. The network checks transactions and uses a consensus mechanism to agree on ledger updates.
  3. New blocks are added to the chain, and participating nodes update their records.

Why Does It Matter?

Blockchains support cryptocurrencies, smart contracts and shared recordkeeping. Depending on their design, they can improve transparency and reduce reliance on a single administrator.

Key Considerations

Blockchains can be public or permissioned. Their security, speed and fees vary. Confirmed records are difficult to change, but a blockchain does not automatically guarantee that submitted data is accurate.