The internet is a truly modern engineering marvel. With billions of people and tens of billions of devices connected to each other, sharing the world's information has never been easier. Since the internet is so accessible and informative, our apparent dependence isn't much of a surprise. Most people would be pretty hard pressed to run their business, stay in touch with friends, and enjoy entertainment without it. Despite the web being crucial to the modern world, few people understand how it works. Let's take a few minutes to discuss some basics.
What is the internet?
These days, computers get lonely. They want friends and want to be able to speak with other computers and devices. When you connect several computers or devices together (with special equipment like switches), you create a network. A network can be small, as little as two devices. Networks can also be very large with thousands of machines. This begs the question: Can you connect networks to one another, then? Why, yes. Yes you can (with special equipment like routers). This very thing is the foundation for the internet as we know it today. The internet is just the largest network of networks in the world. It's really that simple.
That's neat. But how does it work?
Generally, information travels around the internet in segments called network packets. For the sake of this conversation, you can think of a packet as a kind of letter. It has a return address, a destination address, and the content of the letter. Those fancy router devices we mentioned before, much like postal workers, know where to direct your packet next so that it ultimately ends up and the intended destination.
These packets aren't that big, however. They have a very modest size limitation (64 kilobytes), and many networking devices have size limits even smaller than that. When you consider the fact that photos are usually megabytes (millions of bytes) large, it's pretty evident that things don't usually fit in one single packet. Therefore, your computer is probably receiving hundreds of packets for each website you visit.
Where are these packets going?
We now know that packets move between devices and networks on routers and switches, but where are they actually going? There are many answers to this question but, in general, they move between a client (usually your device) and some kind of server. A server is usually what you want to communicate with since they provide useful network services. When you're sending an email, you're exchanging packets with an email server through routers and switches. When you navigate around a website, you're exchanging packets with a web server through, you guessed it, routers and switches. There are countless types of servers that you interact with, many of which happen behind the scenes and without your knowledge.
Just like anything else, someone has to manage all of these routers (there are probably 10-15 different devices between you and most of your destinations), switches, and servers. Between the devices themselves, the staffs that maintain them, and (possibly) attackers, your data passes through many potentially prying eyes. Due to the sheer number of people and devices involved, and the fact that the internet itself is a largely a gentleman's agreement between everyone, securing your data in transit is a monumental challenge. Luckily, some really smart math people have come up with the beginning of a solution to keeping your data private - encryption. What is encryption? How does it work? These topics (and more!) will be covered in our blog soon are covered in this post.