Crypto Fundamentals
What Is Bitcoin
Coins, exchanges, and wallets — the practical building blocks.
In this lesson
- Bitcoin's fixed supply and why it matters
- Who controls the Bitcoin network
Key takeaways
- 1Bitcoin is hard-capped at 21 million coins
- 2No person or company controls it — rules are enforced by the network
- 3Scarcity plus decentralization underpins its 'digital gold' thesis
Lesson summary
Bitcoin is a monetary network built around a scarce asset, a public ledger, and rules that no single company can change at will.
Mental model
Getting Bitcoin straight
Bitcoin is a monetary network built around a scarce asset, a public ledger, and rules that no single company can change at will. Its core promise is predictable issuance and open verification.
- Bitcoin's fixed supply and why it matters
- Who controls the Bitcoin network
Mechanics
How to reason about Bitcoin
New bitcoin is issued through mining according to a programmed schedule.
The maximum supply is capped at 21 million BTC.
Nodes enforce the rules, so social consensus matters as much as software.
- Bitcoin is hard-capped at 21 million coins
- No person or company controls it — rules are enforced by the network
- Scarcity plus decentralization underpins its 'digital gold' thesis
Example
Bitcoin, applied
When a halving reduces new issuance, miners receive fewer new coins per block, but existing holders do not need a bank to confirm the supply schedule.
Common mistakes
Common mistakes with Bitcoin
Bitcoin is not controlled by Satoshi, miners alone, or exchanges. Influence exists, but rule changes require broad network adoption.
Risk notes
Staying safe around Bitcoin
Bitcoin users still face price volatility, key loss, fee spikes, and custody failures if they leave coins with a third party.
- State the supply cap.
- Explain who enforces rules.
- Separate Bitcoin custody from Bitcoin exposure.
Practice
Put Bitcoin to work
- State the supply cap.
- Explain who enforces rules.
- Separate Bitcoin custody from Bitcoin exposure.
Review
Key terms
- Bitcoin (BTC)
- The first cryptocurrency, launched in 2009 — a decentralized, hard-capped (21M) digital money.
- Block
- A batch of transactions bundled together and cryptographically linked to the previous block.
- Custody
- Who controls the private keys. Custodial = a third party holds them; non-custodial = you do.
- Volatility
- How sharply a price swings over time — higher volatility means higher risk and opportunity.
- Satoshi (Sat)
- The smallest unit of Bitcoin — one hundred-millionth (0.00000001) of a BTC.
Source notes
Editorial references
These references are starting points for verifying the mechanisms, risk checks, and product context behind this lesson.
Before you continue
Can you do these?
- State the supply cap.
- Explain who enforces rules.
- Separate Bitcoin custody from Bitcoin exposure.
Related learning
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Bitcoin's maximum supply is capped at…