Blockchain is a decentralized digital database

Definition

Blockchain is a decentralized digital database or ledger that securely stores records across a network of computers in a way that is transparent, immutable, and resistant to tampering. Each "block" contains data, and the blocks are linked in a chronological "chain."

Key Takeaways

• Blockchain is a type of shared database that differs from a typical database in the way it stores information; blockchains store data in blocks linked together via cryptography.
• Different types of information can be stored on a blockchain, but the most common use has been as a transaction ledger. 
• In Bitcoin’s case, the blockchain is decentralized, so no single person or group has control—instead, all users collectively retain control.
• Decentralized blockchains are immutable, which means that the data entered is irreversible. For Bitcoin, transactions are permanently recorded and viewable to anyone.

What Is a Blockchain?

A blockchain is a distributed database or ledger shared across a computer network's nodes. While it is best known for its crucial role in cryptocurrency systems, maintaining a secure and decentralized record of transactions, blockchains are not limited to cryptocurrency uses. Blockchains can be used to make data in any industry immutable, meaning it cannot be altered.

Since a block can’t be changed, the only trust needed is at the point where a user or program enters data. This reduces the need for trusted third parties, such as auditors or other humans, who add costs and can make mistakes.

Since Bitcoin's introduction in 2009, blockchain use has exploded due to the creation of various cryptocurrencies, decentralized finance (DeFi) applications, non-fungible tokens (NFTs), and smart contracts. Bitcoin and other popular cryptocurrencies, such as Ethereum and Solana, can be purchased through leading crypto exchanges