An editorially independent publication supported by the Simons Foundation.
No device is an island: Your daily computational needs depend on more than just the microprocessors inside your computer or phone. Our modern world relies on “distributed computing,” which shares the computational load among multiple different machines. The technique passes data back and forth in an elaborate choreography of digital bits — a dance that has shaped the internet’s past, present and likely future.
In 1973, Xerox engineers invented the ethernet connection, which allowed the first personal computers to communicate with a shared printer. Ethernet gave rise to local area networks (LANs), which by the end of the 1970s let users share files within homes or offices.
Around that same time, the Advanced Research Projects Agency (ARPA) had been developing a more expansive distributed network. ARPANET, as it was called, could distribute information over phone lines, promising a much vaster network than a LAN. But it had limitations: The machines involved had to be compatible, and all connections were hardwired. Defense officials wanted tanks, planes and ships to communicate wirelessly, and scientists wanted to open the networking possibilities up to the masses. The challenge was to establish rules that standardize how any kind of machine talks to another one over any kind of connection.