Learn Bitcoin from first principles

Bitcoin Basics

Start from zero. What Bitcoin is, what a coin actually is, and why it works without anyone running it.

• What Is Bitcoin? A First-Principles Introduction

How It Works

Under the hood: proof of work, blocks, keys, issuance and the fee market.

• How Bitcoin Mining Actually Secures the Network

Guides & Tutorials

Doing things safely: custody, backups, fees, verifying what you are told.

• How to Set Up Self-Custody: A Careful, Unhurried Guide

Nobody runs Bitcoin

There is no company, no server and no administrator. Thousands of independent nodes each check every rule, and a block that breaks one is rejected no matter who produced it.

Supply is fixed, and you can verify it

Issuance follows a schedule written into the software: the block reward halves every 210,000 blocks, converging just under 21 million. Every node enforces it independently.

Keys are ownership

Coins are not in an account. They are outputs on the chain that can only be spent by whoever holds the corresponding private key. There is no recovery process.

The seed phrase is the key

Those twelve or twenty-four words derive every key in your wallet. Anyone with them has your coins. No legitimate service ever needs to see them.

Proof of work is brute force, not cleverness

Miners guess enormous numbers of values until a hash falls below a target. It is expensive to produce and instant to check, and that asymmetry is the entire security model.

Block space is scarce on purpose

Only so much fits every ten minutes, so users bid for inclusion in satoshis per virtual byte. That auction is why fees rise when the network is busy.

Confirmations are a probability, not a switch

Each block on top of yours makes reversal more expensive. Six confirmations is a convention for large amounts, not a protocol rule.

Bitcoin is pseudonymous, not anonymous

Every transaction is public forever. Addresses can be linked to each other and often to people. The ledger does not forget.

Addresses are not people

One person can generate thousands; one exchange can serve millions from a handful. Any metric that counts addresses as users is measuring something else.

Transactions cannot be undone

There is no chargeback, no support line and no reversal. This is what removes the need for a trusted intermediary, and it is why verification before sending matters.