Definition: A distributed ledger technology that records transactions across multiple computers so that the record cannot be altered retroactively without the alteration of all subsequent blocks and the consensus of the network.

Explanation: A blockchain is composed of a series of blocks, each containing a list of transactions. Each block is linked to the previous one through cryptographic hashes, creating a chain of blocks.

Definition: The distribution of power away from a central authority to a network of nodes.

Explanation: In a decentralized system, no single entity has control over the entire network. This structure enhances security and trust, as it eliminates single points of failure and reduces the risk of manipulation.

Definition: A computer that participates in the blockchain network by validating and relaying transactions.

Explanation: Nodes store a copy of the blockchain and work to ensure the accuracy and security of the data by validating transactions and blocks.

Definition: A function that converts an input (or 'message') into a fixed-size string of bytes. The output, known as the hash value, is unique to each unique input.

Explanation: Hashes are used in blockchain to link blocks together. Each block contains the hash of the previous block, ensuring the integrity and immutability of the entire chain.

Definition: The practice of secure communication techniques that allow only the sender and intended recipient of a message to view its contents.

Explanation: Cryptography is used in blockchain to secure transactions and control the creation of new units of cryptocurrency. It ensures that data is transmitted securely and that only authorized parties can access it.

Definition: A process used in blockchain systems to achieve agreement on a single data value or a single state of the network among distributed processes or systems.

Explanation: Common consensus mechanisms include Proof of Work (PoW) and Proof of Stake (PoS). These mechanisms ensure that all participants in the network agree on the validity of transactions and the state of the blockchain.

Definition: A consensus mechanism that requires network participants (miners) to solve complex mathematical problems to validate transactions and add them to the blockchain.

Explanation: PoW is used by Bitcoin and other cryptocurrencies. It requires significant computational power, making it secure but energy-intensive.

Definition: A consensus mechanism that assigns the right to validate transactions and create new blocks to participants based on the number of coins they hold and are willing to "stake" as collateral.

Explanation: PoS is considered more energy-efficient than PoW and is used by cryptocurrencies like Ethereum 2.0 and Cardano.

Definition: Self-executing contracts with the terms of the agreement directly written into code.

Explanation: Smart contracts automatically enforce and execute the terms of a contract when predetermined conditions are met. They are used to facilitate, verify, and enforce the negotiation or performance of a contract.

Definition: The inability to be changed or altered.

Explanation: Once data is recorded on the blockchain, it cannot be changed or deleted. This immutability ensures the integrity and trustworthiness of the data.