A diagram of the ARPANET in 1983, which was the year that it adopted TCP/IP

The internet provides us with many conveniences, from the ability to shop online to connecting with friends and sharing personal and professional documents. At the heart of the internet is the ability for computers to talk to each other in a safe, secure way. Each computer must be able to take the information it wants to send (e.g., an email), package it into one or more messages that correctly arrive at their destination, and similarly be able to receive and interpret messages sent back. This ability to communicate was created using government funding from the Defense Advanced Research Projects Agence (DARPA). It consists of the Transmission Control Protocol (TCP), Internet Protocol (IP), and User Datagram Protocol (UDP). Together packaged as the more well known TCP/IP, these protocols are often considered the “backbone of the internet”.

One of the important parts in internet communication is the encoding of messages into discrete packets, for easy sending. TCP/IP began moving that job from the hardware, which could be different across computers from different manufacturers, to software, making the internet more universally available regardless of the device. The TCP/IP protocols also soved a number of major challenges in making the internet function, including ensuring ordered messages, helping to correct errors as messages get transferred to their destinations, and correctly identifying the computer that is supposed to receive the messages.

In 1983, ARPANET, one of the early precursors of the internet, began using TCP/IP. It’s been the backbone of the internet ever since.