Where Bitcoin came from
The 2008 whitepaper, the mysterious Satoshi Nakamoto, the 2009 genesis block, and the problem Bitcoin was designed to solve.
Bitcoin is a digital currency that runs without a central bank or company. To understand why it exists, it helps to start with its story.
The 2008 whitepaper
On October 31, 2008, a person or group using the name Satoshi Nakamoto published a short paper called "Bitcoin: A Peer-to-Peer Electronic Cash System." A whitepaper is a document that explains a new idea or system. This one described how people could send money directly to each other online without a bank in the middle.
The timing is often linked to the 2008 global financial crisis, when trust in banks was low. Satoshi's paper did not depend on that crisis, but the first block contains a message that points to it, as you will see below.
The problem Bitcoin solved
Digital files are easy to copy. If money is just a file, what stops someone from spending the same coin twice? This is called the double-spending problem. Banks solve it by keeping a central ledger. Bitcoin solved it with a public, shared ledger (the blockchain) secured by proof of work, so thousands of independent computers can agree on who owns what without trusting a single keeper.
The genesis block
On January 3, 2009, the first Bitcoin block, called the genesis block, was created. Satoshi included a newspaper headline inside it: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks." It acts as a timestamp and is widely read as a comment on the banking system.
One of the earliest well-known real-world purchases with bitcoin happened in May 2010, when programmer Laszlo Hanyecz paid 10,000 BTC for two pizzas. At the time, bitcoin had very little market value. The story is often told to show how far the price later moved, but it is also a reminder of how uncertain the value of a new asset is.
Who is Satoshi?
Nobody has publicly proven who Satoshi Nakamoto is. Satoshi communicated by email and forums, worked with early developers, and then stepped away around 2010 to 2011. Many people have claimed to be Satoshi or been named by the media, but none has provided convincing proof.
Open source and no owner
Bitcoin's software is open source, meaning anyone can read, check and propose changes to the code. No company owns Bitcoin. Changes are adopted only if enough users, developers and miners choose to run the new software. This makes Bitcoin slow to change, which supporters see as a strength and critics see as a weakness.
A free account tracks lessons, unlocks the quizzes and gives you 10,000 virtual USD (no real value) to practise with.