Bitcoin is the first CryptocurrencyCryptocurrencyA digital currency secured by cryptography and recorded on a shared ledger, with no bank or government issuing or controlling it. ever created and has always been the largest by market capitalisation. The idea was described in 2008, and the first block was created on 3 January 2009. No bank, government or company controls Bitcoin. Its rules are built into software that thousands of computers around the world run.
Bitcoin or bitcoin?
The word is used in two ways. With a capital letter it means the system itself, the Bitcoin network. In lower case it means the currency, the units you buy, hold and send. One bitcoin is divided into 100 million satoshisSatoshi (sats)The smallest unit of bitcoin: one satoshi is one hundred-millionth of a bitcoin, or 0.00000001 BTC., so you can own a small fraction of one.
Key features
- Limited supply. There will never be more than 21 million bitcoin. This maximum supplyMaximum supplyThe largest number of units of a cryptocurrency that can ever exist under its rules, such as 21 million for bitcoin. is written into the rules of the system.
- Public ledger. Every transaction is recorded on a BlockchainBlockchainA public ledger where transactions are grouped into blocks, each linked to the one before, so past records can't be altered without it showing. that anyone can inspect.
- Proof of work. New bitcoin are created through MiningMiningThe process in which computers compete to solve a puzzle so they can add the next block to the blockchain and earn new bitcoin and fees., where computers compete to add the next block to the chain.
- No middleman. You can send bitcoin anywhere in the world, at any time of day.
What to keep in mind
The price of bitcoin swings a lot and has often fallen by more than half within a few months. Transactions can't be reversed, and whoever holds the private key controls the bitcoin. Bitcoin is not legal tender, and nobody guarantees its value.
Everything in Myntkaup Learn is written and regularly reviewed by the Myntkaup editorial team. It is for education and is not investment advice. Editorial policy. Updated 18 October 2026.