What Is Advanced Research Projects Agency Network (ARPANET)?

It's easier to imagine a world with the Internet. But before there was the World Wide Web and even a "world," Advance was the Advanced Research Projects Agency Network for advanced research. It was conceptualized in the 1950s by computer scientists who needed something better than unreliable switching nodes and network links. ARPANET paved the way for modern telecommunications, allowing scientists to quickly share information across great distances. Today it's hard to imagine life without it—but this is just one example of how ideas can change the world! The early Internet was a wild, wild place. It was a time when computers were massive, expensive machines that took up whole rooms and were only available to the few who had access to them. These computers also didn't talk to each other. If you wanted to get your information from one computer to another, you had to get on your horse and ride to it yourself (or hire someone). But then came along the Advanced Research Projects Agency (ARPA), which understood that if computers were going to be useful for anything more than calculating Pi fast, they needed a way to talk to each other. So, imagine you're an NSA agent and sitting in front of your computer at home. You've just been given the order to take down a network critical to the U.S. government's function during the Cold War. It's called the ARPANET and serves as the backbone for communications between its users. What would be your first step if you were thinking about how to do this? Would you hack into each node in the network and shut them down one by one? Or would you target one significant node—like a server farm—and then use that as leverage against all the others? Probably not! Because if those servers go down, all of those nodes will still be able to communicate with each other using backup channels until another server farm can be brought online. Instead of taking out each node individually, why not just go straight for the source? The ARPANET was built on top of a simple idea: Can we connect all these different computers so that they can simultaneously communicate with each other regardless of which node goes down or gets taken out by hackers, spies, or whatever else? Well, then, we'll have something.