Digital currency and blockchain
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The teaching part (1 min) is free to watch. A free account opens the whole lecture: 6 practice questions, 2 real past-paper questions with the answers explained, the mistakes that lose marks, the full-marks tip, a one-card summary and a quick quiz.
What this lecture covers
- Money you cannot touch
- What is digital currency?
- Who is in charge?
Read the transcript of the teaching part
Last time
Before we start: last time, in The internet, the web and how a page is retrieved, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.
Money you cannot touch
Some money has no coins, no notes, and no plastic card. It exists only on computers. So how can anybody be sure that a payment really happened, and that nobody has cheated? The answer is a shared record called a blockchain.
What is digital currency?
A digital currency is money that exists only electronically. It has no physical form: there are no coins and no notes. It can be used to pay for goods and services. It is usually encrypted, to keep the payments secure.
Who is in charge?
Some digital currencies are centralised, controlled by one organisation. Many, such as cryptocurrencies, are decentralised. Decentralised means no bank or government is in the middle of the payment. A network of computers does the checking instead.
Chapter 5.2: Digital currency
- Digital currency and blockchain 6 min
Also for IGCSE Computer Science 0478
Which topics come up most in IGCSE Computer Science 0478 past papers, counted from every paper since 2004: Paper 1 topic frequency, Paper 2 topic frequency.