What is the Blockchain?

A blockchain is an electronic ledger (database), which operates independently of a central authority, and is controlled by a network of computers around the world.

For example, Ethereum is a decentralized blockchain platform that establishes a peer-to-peer network that securely executes and verifies application code, called smart contracts. Smart contracts allow participants to transact with each other without a trusted central authority. Transaction records are immutable, verifiable, and securely distributed across the network, giving participants full ownership and visibility into transaction data.