What is blockchain technology?

Blockchain is a distributed database that stores records in linked groups (blocks) forming a chronological chain maintained across thousands of computers simultaneously rather than in one central location.

Think of it as a shared document that:

• Thousands of people have a copy of simultaneously
• No single person controls or can alter
• Records every change permanently and transparently
• Requires network-wide agreement to add anything new

How a blockchain works:

1. A transaction is initiated (e.g., sending cryptocurrency, recording a contract)
2. It is broadcast to a peer-to-peer network of computers (nodes)
3. The network validates the transaction using consensus mechanisms (Proof of Work or Proof of Stake)
4. Validated transactions are grouped into a new block
5. The block receives a cryptographic hash (unique fingerprint) and is added to the chain
6. The updated chain is distributed to all nodes — the record is permanent

Properties:

Major applications: Cryptocurrency (Bitcoin, Ethereum), smart contracts, supply chain tracking, healthcare records, digital voting, NFTs, cross-border payments