Bitcoin is not under anyone's control
A network of hundreds of thousands of computers, and what decentralization actually means in practice.
In today's world, people are accustomed to dealing with money that is managed by governments and central banks. Currencies like the U.S. dollar change over time, because a small group of people can influence their fundamental nature. The dollar that was originally created in 1792 looks very different from the dollar that exists today. This is the result of two centuries of incremental adjustments made by people in positions of power.
A timeline of tampering
Today's dollar is a different currency than the original dollar.
A form of digital money outside anyone's control seems like a contradiction. Most digital systems are centralized — such as websites, apps, and your bank account. The underlying software runs on a server somewhere, and specific individuals have access to shutting these services down or pushing updates. This is the familiar model.
However, bitcoin is not like the dollar or other centralized digital systems. Instead of running on a handful of servers at specific locations, bitcoin operates as a network of hundreds of thousands of tiny computers distributed worldwide. Anyone can voluntarily join the network, and no one computer has more power or importance than another. If any one of the computers in the network goes offline, or even if a large percentage of them do, bitcoin will continue to function.
Different types of networks
See which can withstand a targeted attack.
Anyone operating a machine connected to the bitcoin network has the power to make changes to their own software, but not to the software running on others' computers. If someone makes edits to critical rules within the bitcoin software (effectively making their own version of bitcoin), then their instance of the bitcoin software will no longer be recognized as a part of the same network. They would be running a program that's no longer considered bitcoin, and they wouldn't be able to participate in the bitcoin economy.
This means that changes across the entire bitcoin network can only be made by a consensus of users agreeing that the change is favorable. If you run an instance of bitcoin software and don't like a proposed change, you can refuse to adopt it. Because of this, no single entity has control over the system as a whole. While making changes to the dollar system is as trivial as announcing new interest rates, bitcoin's monetary policy has remained the same from the time it was first invented.