Which term describes a decentralised, distributed and public digital ledger used to record transactions across many computers so that the record cannot be altered?

Which term describes a decentralised, distributed and public digital ledger used to record transactions across many computers so that the record cannot be altered?

• A. Centralized ledger
• B. Public ledger
• C. Blockchain
• D. Distributed ledger

Answer: (C)

This item is testing how the description maps to a technology that is decentralised, distributed, and immutable. Blockchain fits because it is a chain of blocks that record transactions across a network of many computers. Each block contains a cryptographic link to the previous one, and the network reaches consensus to agree on the same history. This makes the ledger append-only and tamper-evident: altering an earlier record would require changing many blocks across a majority of nodes, which is practically infeasible. The result is a publicly readable, shared ledger where transactions are recorded in a way that cannot be easily altered. Other terms may describe aspects of ledgers, but they don't simultaneously capture decentralisation, distribution, public access, and immutability like blockchain does.

This item is testing how the description maps to a technology that is decentralised, distributed, and immutable. Blockchain fits because it is a chain of blocks that record transactions across a network of many computers. Each block contains a cryptographic link to the previous one, and the network reaches consensus to agree on the same history. This makes the ledger append-only and tamper-evident: altering an earlier record would require changing many blocks across a majority of nodes, which is practically infeasible. The result is a publicly readable, shared ledger where transactions are recorded in a way that cannot be easily altered. Other terms may describe aspects of ledgers, but they don't simultaneously capture decentralisation, distribution, public access, and immutability like blockchain does.