The Minastany Library

How a Blockchain Works

A blockchain is a shared record book no single party controls. Here's the journey of one transaction — and the two ways networks agree it's real.

01
A request
Someone wants to send value to someone else.
02
The network checks
Thousands of independent computers (nodes) verify it against the rules.
03
Locked in a block
Once the network agrees, the transaction is sealed into a block — encrypted, permanent.

How does the network agree — with no one in charge?

Two systems decide who adds the next block and earns the reward. Both make honesty cheaper than cheating.

Proof of Work
Solve to win — "mining"

Computers race to crack a hard math puzzle. The winner adds the block and earns coins. Faking the record would cost more computing power than the entire rest of the network combined — so cheating doesn't pay.

Used by Bitcoin · energy-intensive
Proof of Stake
Stake to win

Participants put up their own coins as a deposit. The network picks a winner at random (bigger stake, better odds). Validate honestly → earn rewards. Try to cheat → lose your deposit.

Used by Ethereum & others · far less energy

Simplified for clarity. A cryptocurrency is the digital token that lives on a blockchain; the reward paid to nodes is what keeps the network running. This is financial education, not personalized advice.

The Minastany Library