What is a blockchain

Lesson 1 of 3 · 5 min

A blockchain is a shared record of transactions. Instead of one bank keeping the book, thousands of computers (nodes) keep the same copy and check every new entry.

How it works

Transactions are grouped into blocks.
Each block points to the previous one, so the history forms a chain.
Nodes agree on the next block by a set of rules called consensus.
Changing an old block would mean redoing all later blocks and convincing most of the network, which is very hard.

What it gives you

You can send value to anyone without asking a bank. Anyone can check the record. But there is no help desk: a payment sent to a wrong address usually cannot be reversed.

What it does not give you

A blockchain does not make a project honest or a coin valuable. It only records who owns what.

For education only. Not financial advice.