What Bitcoin Is and How It Works

Bitcoin is digital money that runs on a network of computers instead of a bank

Bitcoin is a form of currency that exists only as data on computers around the world. Unlike dollars in your bank account, which a bank holds and manages for you, bitcoin is stored in a digital wallet that you control directly. No bank, government, or company sits in the middle — the network of computers running bitcoin software keeps track of who owns what.

When you send bitcoin to someone, that transaction gets recorded on a public ledger called the blockchain. The blockchain is a chain of records, or "blocks," that link together in order. Each block contains a list of transactions. Once a transaction is recorded on the blockchain, it cannot be changed or deleted — that permanence is one of bitcoin's core features.

Bitcoin was created in 2009 by someone or a group using the name Satoshi Nakamoto. The identity of the creator remains unknown. The software that runs bitcoin is open-source, meaning anyone can read the code and see how it works.

Key Takeaways

• Bitcoin is digital currency stored in a wallet you control, not held by a bank or government.
• All bitcoin transactions are recorded on the blockchain, a permanent public ledger that cannot be altered.
• Bitcoin has a fixed supply cap of 21 million coins, which is built into the software and cannot be changed.
• You can buy bitcoin on exchanges, receive it as payment, or earn it through mining, though mining requires specialized equipment.
• Bitcoin's price changes constantly based on demand and market conditions, and the value can rise or fall significantly.

How bitcoin transactions work

When you send bitcoin, you use your wallet's private key — a long string of characters that acts like a password — to sign the transaction and prove you own the bitcoin you're sending. The transaction is broadcast to the network of computers running bitcoin software, called nodes. These nodes check that you actually own the bitcoin and that the transaction is valid.

Specialized computers called miners bundle pending transactions together into a new block and add it to the blockchain. Miners compete to solve a complex math problem, and the first one to solve it gets to add the block and receives newly created bitcoin as a reward. This process is called proof of work. Once a transaction is recorded in a block and added to the chain, it is considered confirmed and cannot be reversed.

The whole process typically takes about 10 minutes on average, though it can vary. Your transaction may show as pending for a few minutes before it appears as confirmed in the blockchain.

The supply of bitcoin and why it matters

Bitcoin has a maximum supply of 21 million coins. This limit is written into the bitcoin software itself and cannot be changed. As of now, roughly 21 million bitcoin have been created through mining, though the exact number changes as new blocks are added to the blockchain.

The rate at which new bitcoin enters circulation decreases over time through a process called halving. Every four years, the reward miners receive for adding a block is cut in half. This means fewer new bitcoin are created, and eventually, no new bitcoin will be created at all. The fixed supply is one reason some people view bitcoin as a store of value — unlike government-issued currency, no central authority can print more of it.

How to get bitcoin

You can obtain bitcoin in three main ways. The most common is to buy it on a cryptocurrency exchange — a website or app where you can trade regular money for bitcoin. Exchanges like Coinbase, Kraken, and Gemini let you link a bank account or debit card and purchase bitcoin. Prices vary slightly between exchanges, and each charges fees for the transaction.

You can also receive bitcoin as payment if someone sends it to you. To do this, you provide them with your wallet address — a string of characters that works like an account number. Anyone can send bitcoin to your address if they know it, but only you can spend it because only you have the private key.

A third way is mining, which means running specialized computer hardware that solves the math problems needed to add blocks to the blockchain. Mining is expensive and requires significant electricity and equipment. For most people, buying bitcoin on an exchange is the practical option.

Bitcoin wallets and how to store bitcoin

A bitcoin wallet is software or hardware that stores your private keys and lets you send and receive bitcoin. There are several types. A hot wallet is connected to the internet — examples include mobile apps like Blue Wallet or web-based wallets. Hot wallets are convenient for spending but carry more risk because they are online.

A cold wallet is not connected to the internet. Hardware wallets like Ledger and Trezor are physical devices that store your private keys offline. Cold wallets are more find but less convenient if you want to spend bitcoin frequently. Paper wallets — your private key printed on paper — are also cold storage but offer no protection if the paper is lost or damaged.

Whichever wallet you choose, your private key is the only way to access your bitcoin. If you lose it, you cannot recover your bitcoin. If someone else gets your private key, they can take your bitcoin. Many people write down their private key or seed phrase (a set of words that can recreate your private key) and store it in a safe place.

Bitcoin price and volatility

Bitcoin's price is determined by supply and demand on exchanges where people buy and sell it. The price changes constantly throughout the day. Unlike a stock, which represents ownership in a company, bitcoin has no underlying business or earnings — its value depends entirely on what people are willing to pay for it.

Bitcoin's price can swing dramatically. It has risen from pennies to tens of thousands of dollars, and it has also fallen sharply. These price swings are called volatility. Volatility is driven by news, market sentiment, regulatory announcements, and large trades. If you own bitcoin, the dollar value of your holdings can change significantly in a short time.

Bitcoin versus traditional money

Bitcoin and government-issued currency like the U.S. dollar work in fundamentally different ways. Dollars are issued and controlled by the Federal Reserve and backed by the U.S. government. Bitcoin is not issued by any government or central authority — it is created through mining and managed by the network itself.

Dollars are reversible: if you send money by bank transfer and make a mistake, you can contact your bank and potentially reverse the transaction. Bitcoin transactions are permanent and cannot be reversed once they are confirmed on the blockchain. Dollars are also insured by the FDIC up to $250,000 per account at most banks. Bitcoin held in a wallet has no insurance — if you lose access to your wallet or it is hacked, there is no protection.

Bitcoin transactions can be faster and cheaper than international wire transfers, especially for large amounts. However, bitcoin requires you to manage your own security, whereas a bank manages security for you.

Frequently Asked Questions

Is bitcoin legal?

Bitcoin is legal in most countries, including the United States, though regulations vary. Some countries restrict or ban bitcoin trading. The IRS treats bitcoin as property, not currency, which affects how you report it on taxes. Check your local laws and tax rules before buying or trading bitcoin.

Can bitcoin be hacked?

The bitcoin network itself is extremely difficult to hack because it is distributed across thousands of computers. However, your personal wallet can be hacked if your private key is stolen or your device is compromised. Using a cold wallet and keeping your private key find significantly reduces this risk.

What happens if I send bitcoin to the wrong address?

Bitcoin transactions cannot be reversed once they are confirmed on the blockchain. If you send bitcoin to an incorrect address, it is lost. Always double-check the address before sending, and consider sending a small test amount first if you are unsure.

How do I report bitcoin on my taxes?

The IRS requires you to report bitcoin transactions. If you buy bitcoin and the price rises, you owe capital gains tax when you sell. If you receive bitcoin as payment, you report it as income at the price it was worth when you received it. Keep records of all your transactions and consult a tax professional for guidance specific to your situation.

Can I use bitcoin to buy things?

Some merchants accept bitcoin as payment, but it is not widely used for everyday purchases. Major companies like Microsoft and AT&T have experimented with accepting bitcoin, but most stores and services do not. Bitcoin is more commonly held as an investment or used for transfers between individuals.