What is Bitcoin?
Bitcoin is a peer-to-peer electronic cash system created by Satoshi Nakamoto and launched in January 2009. It combines Proof of Work, a UTXO ledger, fixed supply of 21 million coins and an open P2P network into the first practical solution to digital scarcity.
Why Bitcoin matters
Understanding Bitcoin is part of building a solid mental model of how Bitcoin, blockchain and Web3 systems actually work. Concepts in the Bitcoin category sit at the foundation of the broader stack — get them right and the rest is far easier.
Learn this interactively
Reading the definition is a start. ZeroToBlock teaches concepts like Bitcoin through hands-on, browser-based simulations. Build the mental model by actually using it:
- Bitcoin 101 — interactive fundamentals course
- Bitcoin Proof of Work — mining, hashing and consensus
- Browse all interactive blockchain courses
Related terms
- Proof of Work — A consensus mechanism that requires computational work to add blocks.
- UTXO (Unspent Transaction Output) — Bitcoin's accounting model: balances as a set of unspent outputs.
- Halving — The scheduled 50% cut in Bitcoin's block subsidy.
- Satoshi (Unit) — The smallest unit of bitcoin: 0.00000001 BTC.
More bitcoin terms
- Address (Bitcoin / Crypto Address) — A public destination for receiving cryptocurrency.
- Block Header — The metadata at the top of each block.
- Block Reward — New coins paid to the miner of a block.
- Difficulty — A parameter that controls how hard it is to mine a block.
- Double Spend — Attempting to spend the same coin twice.
- Hash Rate — The total computational power securing the network.
- Mining — Producing new blocks by performing Proof of Work.
- Nakamoto Consensus — Bitcoin's consensus rule: follow the chain with the most work.
Keep exploring
Continue with the full blockchain glossary — 136 terms in total — or read the developer blog and FAQ for deeper context.