This article is general education about technology, not financial, tax or legal advice, and it does not recommend buying any asset. Crypto assets are volatile and you can lose everything you put in. Rules differ by country.
Bitcoin is the best-known cryptocurrency, and also one of the most misunderstood. Is it money? A technology? A gamble? We read the project's own FAQ at Bitcoin.org, a self-custody wallet company's explainer (Proton, which promotes its own wallet), the US Federal Trade Commission's consumer guidance and the IRS's digital-asset page, and merged them into a plain-English overview that puts the risks right next to the ideas.
Key takeaways
- Bitcoin is a decentralised digital money. A public ledger, the blockchain, records every transaction.
- Supply is capped at 21 million coins, released on a schedule that halves over time.
- Transactions are generally irreversible, and if you lose your keys, you lose your coins.
- The price is highly volatile, crypto is not insured like bank deposits, and scams are common.
What Is Bitcoin?
According to Bitcoin.org, Bitcoin is a decentralised digital money and payment network with no central authority: users control it collectively, and it works like cash for the internet. Most people interact with it through a wallet app. Unlike a bank balance, you do not have an account with a company; you hold keys that let you move coins on the network.
The Blockchain: A Shared Public Ledger
Every transaction is recorded on the blockchain, a shared ledger kept by many independent computers (nodes). Transactions are grouped into blocks and each block references the one before it. Digital signatures let the owner of an address authorise spending, and nodes independently check each transaction against the protocol's rules. Because the ledger is public, anyone can inspect it. Addresses are not tied to names, but the FTC points out that crypto is traceable rather than truly anonymous.
Mining and Proof of Work
New transactions are confirmed by miners, who use specialised computers to find valid blocks. The first to succeed adds the next block and earns newly issued bitcoin plus transaction fees. The network adjusts the difficulty so a block arrives about every ten minutes on average. This competitive process, called proof of work, secures the ledger, and it needs a lot of computing power and electricity, which is why most mining is done by specialised operations. Each block added on top of a transaction makes it harder to reverse; many people treat six confirmations as a high level of certainty.
The 21 Million Cap and Halvings
Bitcoin.org explains that issuance is capped at 21 million coins. The reward for finding a block halves roughly every four years. Proton notes the most recent halving at the time of its writing was in April 2024, cutting the reward from 6.25 to 3.125 BTC. A coin is divisible down to 0.00000001 BTC, called a satoshi. Scarcity is part of the story people tell about Bitcoin's value, but scarcity does not guarantee a price.
Fees and Confirmation Times
Fees depend on the transaction's size in bytes and on current demand for block space, not on the amount you send. Busy periods mean higher fees and slower confirmation.
Wallets and Keys
- A wallet manages the keys that control your coins. In self-custody you hold the keys yourself and are responsible for them; lost keys mean lost funds.
- A recovery (seed) phrase can restore a wallet. Never share it. Legitimate services never ask for it.
- Hot wallets (connected to the internet) are convenient for spending; cold storage is generally safer for long-term holdings.
Read our full guide to crypto wallets.
The Risks, Plainly
- Volatility. Bitcoin.org itself warns the price is highly volatile and no return is guaranteed. The FTC adds that prices can swing sharply within hours.
- No insurance. The FTC notes crypto is not insured by the government like FDIC-backed bank deposits.
- Irreversibility. Transactions are generally final, so check the full receiving address before sending. If you send funds to the wrong person, recovery is often impossible.
- Key loss and theft. No one can recover your coins if you lose your keys, and anyone who gets your recovery phrase can take them.
- Scams. Guaranteed returns, urgent payment demands and anyone asking you to "unlock" funds are red flags. See crypto scams and how to avoid them.
- Exchange risk. Proton notes that if you leave coins on an exchange you do not fully control them.
Taxes in One Paragraph
In the US the IRS treats digital assets as property and says you must keep records of each purchase, receipt, sale or exchange and its US dollar value at the time. Selling or spending crypto can create taxable gains or losses, and rules differ widely by country, so check with a local tax professional.
Bitcoin vs Other Crypto
Bitcoin is mainly a store of value and payment network. Other networks add programmable features: see our guide to Ethereum and smart contracts and stablecoins.
Before You Do Anything
- Learn how it works and how you could lose money.
- Only consider amounts you can afford to lose entirely; read crypto risks for beginners and, for general investing principles, how to start investing with little money.
- If you decide to buy, follow how to buy crypto safely.
The Business Angle
If you run a website or store and wonder whether to accept crypto, see how to accept crypto payments. Node-devs can integrate payment options into your site.
References and further reading
This guide was compiled from the sources below. We compared them, kept the points they agree on and wrote the article in our own words. Check the originals for more detail.
- Bitcoin FAQ (Bitcoin.org)
- How does Bitcoin work? (Proton)
- What to know about cryptocurrency and scams (US Federal Trade Commission)
- Digital assets (US Internal Revenue Service)
