What Is a Cryptocurrency
Both are digital. That was never the difference.
A euro in your account and bitcoin in a wallet both live in software, both pay electronically, both sit in an app. What separates them is who controls the system, how ownership is proved, and whom you have to trust.
The problem
Prove this balance is yours.
Same value on both sides, both of them digital. Each side rests on conditions. Break one and find out what actually happens.
Two balances, two sets of conditions
ILLUSTRATIVE MODELFour conditions. The figure above is illustrative — the conditions under it are the point.
One condition. It is the only one in your hands — and the only one nobody else can repair.
Both balances are reachable. Click any condition on either side to break it.
Nothing about the technology changed just now. Both balances are still entries in a record. What changed is the answer to one question: who has to be relied on for you to keep access? That question, not the word digital, is what separates the two columns.
Neither side wins here. Bank money puts four conditions in someone else's hands — and in exchange that someone can put things right: records get corrected, access gets unblocked, deposit protection covers part of a failure. Key-based ownership puts one condition in yours — and in exchange there is nobody to appeal to. The difference is structural: who controls the system, how ownership is proved, and whom you must trust.
The definition
Three claims worth turning over.
Tap each card for what sits behind it.
Hands on
Four questions, answered twice.
Switch models and read what changes. The questions stay put — only the answers move.
Digital money
Neither column is a recommendation. They are two different system designs, with different things going wrong in different ways.
The bridge
Where this leaves you.
Four checkpoints, from the word that misleads people to the question the next lesson opens.
Digital money carries fiat into electronic form. Crypto builds a different model for digital value: network-based verification in place of central account-keeping. Which points straight at the more general question — what a centralised system actually is, what a decentralised one costs, and where each of them wins. That is the next lesson.
Check yourself
Five questions.
Answers come straight from this lesson. Submitting completes it.