What Bitcoin Is and How It Works as a Cryptocurrency

Bitcoin is a digital currency that exists only as code, not as physical coins or bills

Bitcoin is a type of cryptocurrency — money that lives on computer networks instead of in your wallet. When you own bitcoin, you hold a digital record that says you own it, stored in a digital wallet (a piece of software or a hardware device). That record is backed by a network of computers that verify and record every transaction, rather than by a bank or government.

Unlike dollars or euros, which a central bank controls and prints, bitcoin is created through a process called mining. Miners are computers that solve complex math problems to add new transactions to the bitcoin network. When a miner solves the problem, they receive newly created bitcoin as a reward. This process is built into bitcoin's code — there will never be more than 21 million bitcoin in existence, a limit written into the system from the start.

You can send bitcoin directly to another person's digital wallet without going through a bank. The transaction is recorded on a blockchain — a permanent, shared ledger that every computer in the bitcoin network keeps a copy of. Once a transaction is recorded on the blockchain, it cannot be changed or reversed.

Key Takeaways

• Bitcoin is digital money that exists as code on a network of computers, not as physical currency you can hold.
• New bitcoin is created through mining, a process where computers solve math problems and are rewarded with newly created bitcoin.
• Every bitcoin transaction is recorded on the blockchain, a permanent ledger that all computers in the network maintain.
• Bitcoin has a fixed supply cap of 21 million coins, which is different from government-issued currencies that can be printed without limit.
• You send and receive bitcoin through a digital wallet, which stores the record of what you own on the blockchain.

How Bitcoin Differs From Regular Money

Regular money — dollars, euros, pounds — is issued and controlled by a central bank or government. A bank can print more of it, set interest rates, and freeze accounts. Bitcoin has no central authority. Instead, the network itself enforces the rules through code that every participant runs on their computer.

When you put money in a bank, the bank holds it and you trust the bank to keep it safe and give it back. With bitcoin, you hold the private key — a long string of characters — that proves you own the bitcoin in your wallet. If you lose that key, no one can recover your bitcoin, not even the people who created it. If someone steals your key, they can take your bitcoin and there is no way to reverse the theft.

Regular money transactions go through a bank or payment processor, which takes time and charges fees. Bitcoin transactions go directly from one wallet to another and are recorded on the blockchain. The network processes transactions continuously, though the speed depends on how busy the network is and how much you pay in transaction fees.

The Blockchain: The Technology Behind Bitcoin

The blockchain is a record-keeping system that makes bitcoin work. Think of it as a ledger that records every transaction ever made in bitcoin. Each "block" in the chain contains a list of transactions and a unique code (called a hash) that links it to the block before it. This chain of blocks goes all the way back to the first bitcoin transaction in 2009.

Every computer in the bitcoin network keeps a full copy of the blockchain. When someone sends bitcoin, the network's computers check that the sender actually owns that bitcoin by looking at the blockchain history. Once enough computers agree the transaction is valid, it gets added to a new block. This distributed system means no single person or company can fake a transaction or change the past.

The blockchain is public — anyone can read it and see every transaction ever recorded. However, transactions are tied to wallet addresses (long strings of characters), not to names, so you can see that money moved from one address to another without knowing who owns each address.

Mining: How New Bitcoin Is Created

Bitcoin mining is the process that creates new bitcoin and secures the network. Miners are computers running specialized software that competes to solve a difficult math problem. The first miner to solve it gets to add the next block of transactions to the blockchain and receives a reward of newly created bitcoin plus transaction fees.

The math problem gets harder as more miners join the network, so the time to solve it stays roughly the same (about 10 minutes per block). This difficulty adjustment is automatic and built into bitcoin's code. Because mining requires significant computing power and electricity, miners are usually large operations with many computers, though individuals can still mine on a smaller scale.

The reward for mining new blocks started at 50 bitcoin in 2009 and is cut in half every four years. This is called a "halving." The reward is now 6.25 bitcoin per block (as of 2024), and it will continue to decrease until it reaches zero. At that point, miners will earn only from transaction fees, and no new bitcoin will be created.

Bitcoin Wallets: Where You Store Your Bitcoin

A bitcoin wallet is software or hardware that stores your private key and lets you send and receive bitcoin. Your private key is the proof that you own the bitcoin associated with your wallet address. Anyone with your private key can take your bitcoin, so keeping it secret is critical.

There are several types of wallets. A hot wallet is connected to the internet — it might be an app on your phone or a website. Hot wallets are convenient for frequent transactions but carry more risk because they are online. A cold wallet is offline — often a hardware device that looks like a USB drive or a piece of paper with your private key written on it. Cold wallets are more find but less convenient for regular use.

If you buy bitcoin through an exchange (a website where you trade regular money for bitcoin), the exchange usually holds your bitcoin in a wallet they control. You do not own the private key in this case — the exchange does. If the exchange is hacked or goes out of business, your bitcoin could be lost. Some people move their bitcoin to a wallet they control themselves to avoid this risk.

Bitcoin's Price and Volatility

Bitcoin's price changes constantly based on supply and demand, just like the price of stocks or gold. The price is set by what buyers and sellers agree to pay on exchanges where bitcoin trades. Because bitcoin is relatively new and the market is smaller than stock or currency markets, price swings can be large and sudden.

Several factors affect bitcoin's price: news about regulation, changes in mining difficulty, large purchases or sales by institutions, and general economic conditions. A single tweet from a public figure or a news story about a country adopting bitcoin can move the price significantly. This volatility means bitcoin's value in dollars (or any other currency) can rise or fall sharply in a short time.

Bitcoin's price history shows large gains and large losses. Someone who bought bitcoin in 2017 at a high price and sold in 2018 would have lost money. Someone who bought in 2020 and held through 2021 would have seen large gains. Past price movements do not predict future ones.

Frequently Asked Questions

Is bitcoin real money?

Bitcoin functions as money — you can use it to buy things and send it to other people — but it is not issued by a government or central bank. Whether it counts as "real money" depends on your definition. It has real value because people will trade it for regular currency, but it is not legal tender in most countries, meaning businesses are not required to accept it.

Can bitcoin be hacked or stolen?

Bitcoin itself cannot be hacked because the blockchain is secured by the network of computers that maintain it. However, your wallet can be hacked if it is online and poorly secured, or your private key can be stolen. If someone gets your private key, they can take your bitcoin and the theft cannot be reversed. This is why security practices — like using strong passwords and keeping private keys offline — matter.

Who created bitcoin and why?

Bitcoin was created by someone or a group using the name Satoshi Nakamoto. Their true identity is unknown. Bitcoin was designed to work without a central bank or government, using code and a network of computers to verify transactions instead. The first bitcoin transaction occurred in 2009.

How many people own bitcoin?

The exact number is unknown because anyone can create a wallet without providing personal information. Surveys suggest millions of people own some bitcoin, but estimates vary widely. Because the blockchain is public, you can see how many addresses hold bitcoin, but you cannot tell how many people that represents — one person might own many addresses.

Can bitcoin be used to buy things?

Some businesses accept bitcoin as payment, including some online retailers, restaurants, and service providers. However, bitcoin is not widely accepted compared to regular currency or credit cards. The number of places that accept bitcoin has grown over time, but it remains a small fraction of all businesses. Transaction fees and the time it takes to confirm a transaction can make bitcoin less practical than other payment methods for everyday purchases.