What Is Bitcoin and How Does It Actually Work?
Bitcoin was designed to be money that doesn't need a bank or government to issue or move it. Here's how that actually works under the hood.
Money without a central issuer
Every traditional currency — the dollar, the euro — is issued and managed by a central bank, which can adjust the money supply and oversees the banking system that moves it around. Bitcoin, launched in 2009, was designed specifically to work without any of that central infrastructure. No single company, bank, or government controls it; instead, it runs on a network of computers around the world, all following the same open-source rules.
The blockchain: a shared, public ledger
At the core of Bitcoin is its blockchain: a continuously growing, public record of every transaction ever made on the network, maintained not by one central database but by thousands of independent computers, called nodes, that each keep their own copy and constantly check it against everyone else's. Our guide to blockchain technology goes deeper into how this actually works. This shared record-keeping is what lets Bitcoin function without a bank verifying transactions — the network verifies itself.
Mining: how new transactions get confirmed
Bitcoin transactions are grouped into "blocks," and specialized computers called miners compete to solve a computationally difficult puzzle to add the next block to the chain. The winning miner is rewarded with newly created bitcoin, plus transaction fees from the block. This process, called proof-of-work, serves two purposes at once: it's how new bitcoin enters circulation, and it's the security mechanism that makes the transaction history extremely difficult to tamper with, since altering past records would require redoing an enormous amount of computational work.
- Anyone can run a node and independently verify the entire transaction history — the system doesn't require trusting a central authority.
- Mining requires substantial computing power and electricity, which has made large-scale mining a specialized, capital-intensive industry.
- Transactions are recorded under wallet addresses, not personal names, which gives Bitcoin a degree of pseudonymity rather than full anonymity.
A hard cap on supply
Unlike a traditional currency, which a central bank can create more of, Bitcoin's protocol caps the total supply at 21 million coins, a limit written directly into its code. New bitcoin is issued to miners on a fixed, slowly declining schedule, roughly halving every four years, until the cap is reached. This fixed, predictable supply is a core part of Bitcoin's appeal to proponents, who compare it to a scarce commodity like gold, though it's also a significant departure from how modern currencies typically work.
A traditional currency's supply is a policy decision, adjusted over time. Bitcoin's supply is a mathematical constant, fixed since the day it launched.
What actually gives it value
Bitcoin has no government backing, no physical commodity behind it, and no cash flows like a stock or bond. Its market value is determined entirely by what buyers and sellers are willing to trade it for, based on their beliefs about its usefulness as a store of value, a means of exchange, or simply as a speculative asset. That makes it a fundamentally different kind of asset to evaluate than a stock or bond, and one whose price has historically been considerably more volatile than most traditional investments.
This article is educational and general in nature. It isn’t personalized investment, tax, or legal advice — always weigh your own circumstances, or talk to a licensed professional, before making financial decisions.