Bitcoin
Learn how Bitcoin works, from what it is to how the network confirms payments. These guides explain why only 21 million bitcoin will ever exist, how one bitcoin splits into 100 million satoshis and what moves the price. You will also learn how private Bitcoin really is, how a Bitcoin ETF differs from owning coins and which risks to weigh before you buy. Bitcoin’s price can rise or fall sharply, and no one can predict where it goes next.
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How are bitcoin amounts measured?
One bitcoin divides into 100 million satoshis, so you can own a small fraction of a coin. These guides explain the units and what a bitcoin actually is.
What should you know before you own bitcoin?
Bitcoin carries real risks, including sharp price falls, and no return is ever certain. These guides set out why people hold it, the main risks and the different ways to get exposure.
How is Bitcoin used and classified?
People use Bitcoin to make payments and to hold as an asset, and authorities classify it in different ways. These guides look at where Bitcoin is used and whether it counts as a commodity.
Key terms
- Satoshi (Sat) A satoshi (sat) is the smallest bitcoin amount the blockchain records: 0.00000001 BTC, so one bitcoin equals 100,000,000 sats.
- Stack Sats Stacking sats is building up bitcoin gradually in small amounts, measured in satoshis (1 BTC = 100,000,000 sats), usually by buying on a regular schedule.
- Halving Roughly every four years, or every 210,000 blocks, the number of new bitcoins created in each block is cut in half.
- Genesis Block The genesis block is the first block of a blockchain, numbered block 0, and every later block links back to it.
- Mempool The mempool (memory pool) is the waiting area where each Bitcoin node holds valid transactions that have not yet been confirmed in a block.
- Lightning Network The Lightning Network is a layer-2 network on top of Bitcoin that lets people send bitcoin payments through payment channels without waiting for block…
- Bitcoin Obituaries Bitcoin obituaries are articles or public statements declaring that Bitcoin is dead or doomed.
Frequently asked questions
What is Bitcoin?
Bitcoin is a digital currency that runs on a public network with no central bank or company in charge. It was created by the pseudonymous Satoshi Nakamoto, launched in 2009, and its rules allow only 21 million bitcoin to ever exist.
Can you buy less than one bitcoin?
Yes. A bitcoin can be split into 100 million units called satoshis, each worth 0.00000001 BTC, so you can buy a small fraction of a coin. The smallest amount you can buy depends on the service and payment method you use.
What is the Bitcoin halving?
The halving is a built-in cut in the number of new bitcoin created with each block. It happens every 210,000 blocks, roughly every four years, and continues until the 21 million limit is reached.
Is Bitcoin anonymous?
No. Every Bitcoin transaction is stored on a public record that anyone can read, including the balance of each address. Addresses do not show names, so Bitcoin is called pseudonymous, but addresses can often be linked to real people.
Can a Bitcoin payment be reversed?
No. Once a Bitcoin transaction is confirmed, it cannot be reversed; only the person who received the funds can send them back. Always check the address before you send.