Basics · Beginner lesson · about 2 minutes
Blockchain
A shared record that many computers can check.
The short answer
A blockchain is a shared record updated under published network rules. It is not automatically private, accurate, or valuable.
In plain English
A blockchain is a shared record updated under published network rules. It is not automatically private, accurate, or valuable.
The details differ by network and service, so use the linked sources and the project’s own documentation when a decision depends on current behavior.
What can go wrong
Read this before you act.
A network’s rules, participants, and data availability matter more than the word blockchain alone.
Check your understanding
A few questions. Not a test.
Pick an answer to see why it's right or wrong. There's no score to unlock.
Sources and corrections
This lesson is a starting point. The two sites below are good general places to learn more. Please tell us if something needs fixing.