Bitcoin: the first blockchain money, run without a central operator
From a 2008 white paper to a 21-million-coin asset
Bitcoin (BTC), launched in January 2009, is the first blockchain and the digital money that runs on it. No bank or company runs it; participants worldwide verify one shared ledger.
1. Who made it
Bitcoin began with a nine-page white paper published on October 31, 2008 under the name Satoshi Nakamoto. The genesis block of January 3, 2009 carries a Times headline about a bank bailout. Satoshi stepped away around 2010–2011, and open-source developers now maintain software such as Bitcoin Core.
There is no company, foundation or CEO. Anyone can run a node, a computer that checks every rule, and rule changes need broad agreement among developers, miners and users. On the Crypto Nation map, BTC is the city-hall tower of Bitcoin City, as that chain’s native coin.
2. Proof of work and 21 million
Bitcoin uses proof of work: miners race to solve a costly computing puzzle, and the winner adds the next block. Blocks arrive about every ten minutes, and difficulty adjusts every 2,016 blocks, roughly two weeks. Rewriting history would mean redoing all later work, so old transactions become practically irreversible.
New coins are created only as block rewards, which halve every 210,000 blocks, about four years. The reward fell from 50 BTC to 3.125 BTC after the fourth halving in April 2024; the next is expected around 2028. Supply can never exceed 21 million BTC, and one satoshi is a hundred-millionth of a bitcoin.
3. Uses and milestones
On May 22, 2010, 10,000 BTC bought two pizzas, the first widely cited purchase. SegWit, which moves signature data aside to save block space, activated in August 2017, the month Bitcoin Cash split off after a block-size dispute. Taproot added Schnorr signatures in November 2021, and the Lightning Network grew for fast, small off-chain payments.
El Salvador made bitcoin legal tender in September 2021, but a January 2025 amendment ended mandatory acceptance. The US approved spot bitcoin ETFs in January 2024, and a March 2025 executive order created a Strategic Bitcoin Reserve from seized coins. Since 2023, Ordinals and similar projects have inscribed images and data on Bitcoin.
4. Things to know
Mining uses a lot of electricity and draws steady environmental criticism. Concentration of hash power in a few large pools and regions is a decentralization concern. Many losses, such as the 2014 collapse of the Mt. Gox exchange, happened at custodians rather than in Bitcoin itself, so control of private keys matters.
When Bitcoin Core 30 greatly raised the default limit on extra transaction data (OP_RETURN) in 2025, some node operators objected and switched to alternatives such as Bitcoin Knots. Possible future quantum threats to today’s signatures, differing taxes and rules, and large price swings are also worth noting.
Written from information public up to October 2026. It does not recommend or rate any coin and is not investment advice. If something is wrong, please tell us through the contact page.