₿ Crypto & Web3 · Lesson 1 of 9 · 8 min
What is Bitcoin?
₿ Two pizzas in 2010 cost a man 10,000 Bitcoin. Those coins are worth roughly $850 million now (over $1.2 billion at the October 2025 peak). He's fine, reportedly. But before you decide he was an idiot, it's worth knowing exactly what he handed over — because most people who say the word 'Bitcoin' could not tell you what it is.
💡 Key idea
Only 21 million Bitcoin will ever exist. Fixed supply = scarcity.
🧠 Why it matters
Bitcoin is digital money nobody controls. No bank. No government. Only 21 million will EVER exist.
🌍 In the real world
🌍 El Salvador made Bitcoin legal tender in 2021 — official money of a whole country (it quietly walked that back in 2025).
📌 Takeaways
- Digital money, no central authority
- 21 million max supply
- Scarcity drives long-term value
📖 Terms in this lesson
Bitcoin: The first cryptocurrency: digital money with a fixed supply, run by a network instead of a bank.
Blockchain: A shared record of transactions that thousands of computers keep in sync so nobody can quietly change it.
✅ Test yourself
Max Bitcoin supply?
- Unlimited
- 1 billion
- 21 million
- 100 million
Answer: C · 21 million
Only 21 million bitcoin will ever exist — it is hardcoded and cannot be changed.
Why does Bitcoin's capped supply matter?
- It makes it scarce, like digital gold
- It makes it free
- It means it expires
- It has no effect
Answer: A · It makes it scarce, like digital gold
Fixed supply means no one can print more. Scarcity is central to Bitcoin's 'digital gold' argument.
Who controls the Bitcoin network?
- A CEO
- The US government
- No single entity — it is decentralized
- A bank
Answer: C · No single entity — it is decentralized
Bitcoin runs on a global network of computers. No company, person, or government controls it.
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