In 1965, Donald Davies, a scientist at Britain’s National Physical Laboratory developed a way of sending information from one computer to another that he called “packet switching.” Packet switching breaks data down into blocks, or packets, before sending it to its destination. That way, each packet can take its own route from place to place. Without packet switching, the government’s computer network—now known as the Arpanet—would have been just as vulnerable to enemy attacks as the phone system.