Programs run on computers, and computers are connected to the Internet. This network was developed in the last 60 years, first to provide military data communication that is resilient to rocket attack, then it was extended to be an academic network, and later it became a commercial network used by anyone and available almost ubiquitously all over the Earth.
The design of the network, and the research, started as a response to the flight of Gagarin over the Earth in the fifties. Sending Gagarin to space and travelling over the Earth was a demonstration that Russia could send a rocket anywhere on the globe, possibly with atomic explosives. It meant that any data network that needed some central control was not resilient to such an attack. It was not feasible to have a network with a central location as a single point of failure. Therefore, research was started to create a network that goes on working even if any part of it is brought down.