The main components of a blockchain include nodes, blocks, transactions, consensus mechanisms, and smart contracts. Nodes are decentralized participants that validate and store data. Blocks contain batches of transactions and are linked to each other in chronological order. Each transaction on the blockchain is recorded securely and immutably. Consensus mechanisms, such as proof-of-work (PoW) or proof-of-stake (PoS), ensure agreement on the blockchain’s state. Smart contracts are self-executing agreements that automatically enforce terms, enabling automation and transparency within decentralized applications.