What Is Bitcoin (BTC)? How It Works, Use Cases and Risks
What is Bitcoin? A plain-English guide to how BTC works, who created it, its 21 million supply cap, what people use it for and the risks to understand first.
Bitcoin (BTC) is the first cryptocurrency: a digital money that runs on a public, decentralized network instead of a bank, with a fixed maximum supply of 21 million coins. Anyone can send, receive and verify bitcoin transactions using open-source software, and no company, government or central server controls the network.
Bitcoin matters because almost every other crypto asset was built in its shadow. Understanding how it works — and where its limits are — gives you a reference point for judging every coin that came after it. This guide is for beginners who want a clear, balanced picture before buying or holding any.
Who Created Bitcoin and When It Launched
On October 31, 2008, Satoshi Nakamoto published the Bitcoin white paper, titled "Bitcoin: A Peer-to-Peer Electronic Cash System." It described how to send money online without a trusted intermediary by solving the "double-spend" problem with a shared public ledger.
The network went live on January 3, 2009, when Satoshi mined the first block, known as the genesis block. Satoshi worked with early developers for about two years and then stepped away. Since then, Bitcoin has been maintained by independent volunteers and companies who contribute to open-source software such as Bitcoin Core. For background on the project itself, see DigiByte (DGB) explained.
There is no Bitcoin CEO, foundation that controls the protocol, or official company. That is a strength — no single party can change the rules — but it also means nobody can reverse your mistakes or refund stolen coins. If Waves is new to you, start with what Waves is and how it works.
How the Bitcoin Network Works
Bitcoin is a blockchain: a chain of blocks, each containing a batch of transactions, linked together with cryptography so that past entries cannot be quietly edited.
Proof of work and mining
New blocks are added by miners using proof of work. Miners run specialized hardware that repeatedly hashes block data (using the SHA-256 function) until it finds a result below a target. The first miner to succeed broadcasts the block, and other nodes check that it follows the rules.
The network adjusts the difficulty every 2,016 blocks so that blocks keep arriving about every 10 minutes, no matter how much mining power joins or leaves. For background on the project itself, see Bitcoin Cash (BCH) explained. Our Ravencoin (RVN) explainer covers the project's basics, use cases and risks.
Nodes and keys
Thousands of independent nodes store a copy of the blockchain and reject any block or transaction that breaks the rules. Your coins are controlled by a private key: whoever holds the key can spend the bitcoin. A wallet is simply software or hardware that manages those keys for you. If Quant is new to you, start with what Quant (QNT) is and how it works.
Upgrades
Bitcoin changes slowly and conservatively. Notable upgrades include SegWit in 2017, which changed how transaction data is stored, and Taproot in 2021, which improved privacy and flexibility for complex transactions. Both were soft forks, meaning older nodes remained compatible. Our Cronos (CRO) explainer covers the project's basics, use cases and risks.
What Bitcoin Is Used For
| Use case | How it works in practice | Things to know |
|---|---|---|
| Store of value | Holding BTC long term as "digital gold" | Prices can fall sharply for long periods |
| Cross-border transfers | Sending value worldwide without a bank | On-chain fees vary with network demand |
| Payments | Paying merchants that accept BTC | Few everyday merchants accept it directly |
| Self-custody savings | Holding funds in your own wallet | You are fully responsible for your keys |
| Small, fast payments | Using the Lightning Network | Requires compatible wallets and channels |
Bitcoin's own scripting language is deliberately limited, so it does not host a large ecosystem of smart contracts the way Ethereum does. In recent years, though, ideas such as Ordinals and inscriptions have added new kinds of on-chain activity.
Bitcoin's Supply Design
Bitcoin's monetary policy is written into the protocol:
- 1Hard cap. No more than 21 million BTC can ever exist.
- 2Block reward. Miners receive newly created bitcoin with each block they mine.
- 3Halvings. Every 210,000 blocks — roughly every four years — the reward is cut in half. Our guide to the Bitcoin halving explains the schedule.
- 4Fees. As the reward shrinks, miners increasingly rely on transaction fees. The final fraction of new bitcoin is expected around 2140.
Some coins have also been permanently lost because owners misplaced their keys, so the number of coins that can actually move is lower than the total issued. For live circulating supply, check the Bitcoin price page. Our Bitcoin price outlook for 2026–2027 looks at the catalysts, risks and bull, base and bear scenarios.
Risks and Criticisms
Bitcoin is the most established crypto asset, but it is not low-risk.
- Volatility. BTC has repeatedly dropped by large percentages in short periods. You could lose a large part of what you put in.
- Irreversible transactions. Sending to the wrong address or falling for a scam cannot be undone.
- Energy use. Proof-of-work mining consumes significant electricity. Supporters argue it secures the network and can use stranded or renewable power; critics argue the environmental cost is too high.
- Scaling limits. The base layer handles a limited number of transactions, so fees can spike when demand is high.
- Regulation. Rules for buying, holding and taxing bitcoin differ by country and keep changing.
- Mining concentration. A large share of mining power is organized through a small number of pools, which critics see as a centralization risk.
How to Avoid Fake Bitcoin and Bitcoin Scams
Because BTC is a native coin, there is no "official contract address" to check on Bitcoin itself. Fakes appear in other forms:
- Look-alike tokens on other blockchains named "Bitcoin," "BTC 2.0" or similar. These are not bitcoin.
- Wrapped bitcoin tokens are legitimate tools in some cases, but each depends on its issuer or bridge. Read our explainer on wrapped tokens before holding one.
- Fake wallets and "Bitcoin doubling" giveaways. Nobody sends back twice what you send.
When a wrapped version is involved, use the steps in our guide on how to verify a token's official contract address. For the coin itself, download wallet software only from its official site and double-check every address before sending.
Bottom line
Bitcoin is a decentralized, capped-supply digital money secured by proof-of-work mining and run by no single company. Its simplicity and track record are its main strengths; volatility, irreversible mistakes and scams are the main risks. Learn how self-custody works, start small, and follow the live price and supply data on the Bitcoin coin page rather than social media hype.
Frequently asked questions
Who created Bitcoin?
Bitcoin was created by a person or group using the name Satoshi Nakamoto, who published the Bitcoin white paper in 2008 and launched the network in January 2009. Satoshi's real identity has never been confirmed, and they stopped communicating publicly around 2010–2011. No company or foundation owns or runs Bitcoin today.
How many bitcoins will ever exist?
The protocol caps the supply at 21 million BTC. New coins are issued to miners as a block reward that halves roughly every four years, so issuance slows over time. The last new bitcoin is expected to be mined around the year 2140, after which miners will rely on transaction fees.
Does Bitcoin have a contract address?
No. BTC is the native coin of the Bitcoin blockchain, so it has no token contract. Tokens on other networks that claim to be bitcoin are wrapped or bridged versions issued by a third party. If someone gives you a Bitcoin contract address on another chain, check carefully who issues that token and what backs it.
Can I buy less than one bitcoin?
Yes. Each bitcoin is divisible into 100 million units called satoshis, or sats. Exchanges and wallets let you buy, send and hold small fractions of a coin, so you do not need to buy a whole bitcoin. The price of one full BTC is simply the unit used for quoting.