How does bitcoin work?

Behind the scenes, the Bitcoin network distributes a public register called the "blockchain." This log contains every transaction ever processed, allowing a user's computer to verify the validity of each transaction. The authenticity of each transaction is protected by digital signatures corresponding to the addresses from which the bitcoins were sent, allowing all users to have full control over the sending of bitcoins from their personal Bitcoin addresses. Additionally, anyone can process transactions using the computing power of specialized hardware and be rewarded with bitcoins for this service. This is often called "mining".

No one controls the Bitcoin network just as no one owns the technology behind email. Bitcoin is controlled by all Bitcoin users around the world. While programmers improve the software, they cannot force a change in the Bitcoin protocol because all users are free to choose which software and which version to use. In order to remain compatible with each other, all users must use software that follows the same rules. Bitcoin can only work properly when there is a consensus among all users. So, all users and programmers have a strong motivation to protect this consensus.