Visual guide4 min
What problem does a blockchain solve?
A shared record is easy to copy. Agreeing which changes count is the harder part.
Read the guideThe learning library
Make sense of the mechanisms.
Follow a question, experiment with an idea, or take the guided path. There’s more than one way to understand.
Start here
Follow a Bitcoin payment
An everyday action connects wallets, outputs, fees, and confirmation. Read the path in order, at your own pace.
01Your wallet, your keys, and your bitcoin: what lives where?
02What actually happens when you send bitcoin?
03UTXOs and change: why one payment can create two outputs
04Bitcoin transaction fees and virtual size
05Pending, confirmed, and reorganized: a payment’s changing status
06How a Lightning channel works
6 published articles
Interactive lesson3 min
Hashing explained: change one character and inspect the result
Turn a message into a fingerprint, then see how a tiny edit changes the result.
Explore the lessonVisual guide4 min
Hashing versus encryption: why they solve different problems
One helps compare data. The other helps keep data confidential. Mixing them up breaks the design.
Read the guideVisual guide3 min
Private keys, public keys, and addresses
Three things often called “a wallet address” do very different jobs.
Read the guideVisual guide3 min
What does a digital signature prove?
A valid signature connects a message to a key. It leaves several other questions unanswered.
Read the guideVisual guide3 min
What nodes check, and why a blockchain needs consensus
Validity, willingness to relay, and choosing a history are three separate decisions.
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