Bitcoin

A peer-to-peer digital currency invented in 2008 by Satoshi Nakamoto. The first money in human history with a fixed supply.

Bitcoin is a peer-to-peer electronic cash system, launched in January 2009 by an anonymous developer (or group) using the name Satoshi Nakamoto. Its core innovation is a way to transfer value over the internet without trusting any central authority — no bank, no government, no payment processor.

Bitcoin is also the name of both the network (the protocol and the global computers running it) and the currency unit (BTC). One Bitcoin is divisible into 100 million sats; you transact in whatever unit makes sense.

The properties that distinguish Bitcoin from every prior form of money: a fixed maximum supply (21 million BTC, never more), a public ledger anyone can verify, a network with no single point of failure, and rules that can only be changed by overwhelming consensus across thousands of independent operators worldwide.

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Course topic

Bitcoin foundations

Start here. What Bitcoin is, where it came from, and why it matters.

Related terms

Glossary

Sats

Short for satoshis — the smallest unit of Bitcoin. 100 million sats = 1 BTC.

Glossary

Satoshi

Two meanings: (1) the smallest unit of Bitcoin (1/100,000,000 BTC), and (2) the pseudonymous inventor of Bitcoin.

Glossary

Blockchain

The public ledger of every Bitcoin transaction, organised into a chain of blocks.

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