IGCSE Computer Science Paper 1 Definitions Worksheet: 5.2 Digital Currency (Modules 510–519)
Name:
Date:
Class:
✎
Key terms
Write what each term means, in your own words.
1
digital ledger
2
ledger record
3
time-stamp
4
immutable
5
immutable record
6
blockchain
7
block
8
chain of blocks
9
decentralised ledger
10
transaction -> time-stamp -> block -> chain
Answer Key
IGCSE Computer Science Paper 1 · Modules 510–519 · Student wording will vary for definitions
1digital ledger — A ledger stored electronically instead of on paper. Records are kept as data on computers, so they are easy to search and copy. Digital currency uses one to track who owns what.
2ledger record — One entry in a ledger that states who sent the money (sender), who received it (receiver) and how much was sent (amount). Each transaction gets its own record.
3time-stamp — The date and time added to a record when it is created, showing when it was made. It puts records in order and shows which happened first.
4immutable — Cannot be changed or deleted once added. A blockchain record stays fixed, so mistakes are fixed by adding a new record and the history stays permanent.
5immutable record — A record that cannot be changed once saved, so no one can cheat by editing an amount or deleting a payment, and everyone can trust the ledger.
6blockchain — A digital ledger: a time-stamped series of records, in order, that cannot be altered.
7block — A group of transaction records saved together with a time-stamp as one unit of the blockchain. When a block is full it is closed, and new transactions go into a new block.
8chain of blocks — Blocks are added one after another in time order. Each new block goes on the end and links to the block before it, so the blocks form a chain.
9decentralised ledger — A blockchain ledger copied on many computers. No one person or company controls it, and a changed copy is spotted by comparing it with the others.
10transaction -> time-stamp -> block -> chain — The order a payment follows: the sender makes it, it is time-stamped, placed in a block, and the block joins the chain, so the record becomes permanent.