What is a blockchain?
The shared ledger that records every crypto transaction.
Beginner 3 min readUpdated 5/27/2026
A blockchain is a shared, public record of transactions, maintained by many computers at once. Each batch of transactions is a "block", and blocks are linked in order — forming a chain that's extremely hard to alter.
Because it's shared and verified by many participants, no single party can secretly change history. This is what lets crypto work without a central bank.