Definition
Blockchain is a distributed database where transactions are grouped into blocks, cryptographically linked in chronological order, and stored across thousands of nodes. Once recorded, data is practically immutable—altering one block would require recalculating all subsequent blocks across the majority of network nodes. This trustless, transparent architecture enables cryptocurrencies, smart contracts, and decentralized applications.
lightbulb Example
When Alice sends 1 BTC to Bob, the transaction is broadcast to the Bitcoin network, verified by miners, included in a block with other transactions, and permanently recorded. Every node has an identical copy of this transaction history.
verified_user Key Points
- Distributed ledger across thousands of nodes
- Immutable—practically impossible to alter
- Enables trustless transactions without intermediaries
- Foundation for cryptocurrencies and smart contracts