01Bitcoin Fundamentals
The Life of a Transaction
Follow one payment from your wallet to the blockchain.
Learning objective: Describe the six stages a payment passes through.
Bitcoin Universe · Understand the invisible.
Understand Bitcoin. From the inside out.
Explore Bitcoin through interactive machines, visual simulations, and hands-on experiments.
20 interactive models3 levels: Easy, Explore, AdvancedNo sign-up, no tracking
Machines you can take apart
- 01
See it
Every idea is a working machine: a vault, a clock, a mining rig, a race track. You recognise what it does before you read a word.
- 02
Change it
Turn the dials, add keys, raise the fee, give the attacker more power. Every number is computed from Bitcoin's real rules or from a clearly labelled simulation.
- 03
Go deeper
Switch between Easy, Explore and Advanced at any time. The same machine explains itself to a child and to an engineer.
Start with these
All 20 models →01
02Network
The Mining Machine
See the guessing game that secures every block.
Learning objective: Explain mining as repeated guessing that is hard to do and easy to check.
15Security
The Bitcoin Security Arena
Why rewriting history gets harder with every block.
Learning objective: Explain why more confirmations make a payment safer.
Five rooms of the museum
- 5 modelsBitcoin FundamentalsWhat a transaction is, where coins really live, how blocks chain together and what a wallet holds.
- 5 modelsSecurityKeeping keys safe, and why rewriting Bitcoin's history gets harder with every block.
- 5 modelsNetworkNodes passing data, miners searching for blocks, the market for space in them, and Lightning payment channels on top.
- 3 modelsEconomicsThe issuance schedule, how monetary systems differ, and Bitcoin's history.
- 2 modelsAdvancedThe difficulty feedback loop and multi-key custody, for learners ready for the mechanics.
Related project
Knowledge gives you understanding. Tools give you choices.
Bitcoin Universe helps you understand the technology. Sitadel explores what user-controlled communication and Bitcoin payments can look like in practice.