Welcome to the first post in our series, “Techsplanations” – our second topic will be the non-physical structures that we engage with as a part of the internet.
For the following posts in this series, please refer to this glossary as a reference for the key terms (in bold) and concepts involved. If you already have a good grasp on the topics presented, consider using this series as an educational entry point for your friends and relatives. For those who would like to have a better understanding of the technologies that shape our everyday lives, whether to make informed decisions about your interactions with technology or to engage with policy and lawmakers at a more granular level, read on.
OK, so the internet is just a bunch of interconnected networks. What happens when I look up a recipe on the internet?
Before we get into the mechanics of how most of us use the internet, let’s talk briefly about the difference between the internet and the web. The internet is the physical network of networks and the logical infrastructure (such as the IP address system) that, in theory, can link your computer to every other thing on any of those networks. It is the wires, cables, and wireless transmission equipment that link real-world devices to each other and to the larger set of interconnected networks. It is also the set of rules and systems these networks share to allow them to communicate with each other and function as a unified network.
The World Wide Web, on the other hand, is made of the virtual spaces and information we and our devices interact with through our connection to the internet. The information that makes up the web is stored on computers and travels across the physical connections of the internet between computers. The information spaces that make up the web are characterized by three common attributes: they organize, refer to, and locate individual files using URLs (Uniform Resource Locators); they utilize hypertext to provide convenient links between sources of information; and they are accessible via the internet. So, when you are reading the news, searching for information, or shopping online, you are interacting with the web, but the information exchanged between your computer and others travels across the internet. We will get to the so-called Internet of Things in a later post, but for now it is enough to say that the IoT is neither the internet nor the web, but rather a subset of devices connected to the internet.
OK, physical components vs. virtual spaces – internet vs. web. Now, what do we do on the web?
Here’s where we talk about how your interaction with the web works over the internet. We will cover most of the basic elements, but there are far more details involved than this post can carry.
The most likely first step is that you open a web browser application on your computer, such as Firefox, Safari, Edge, Opera, or Chrome. At this point, you may choose to click on a page or type a web address (either a URL or an IP address) directly into the address bar. Once you click or press the return key, a whole bunch of steps (which we will simplify below) happen in the fraction of a second (or few seconds) it takes to display on your computer the website you selected.
First, your browser does you a big favor. It takes the text-based address you typed or clicked (for example, https://staging.cdt.org), contacts a Domain Name System (DNS) resolver, and looks up the correct Internet Protocol (IP) address for the domain you asked for. DNS is essentially the phone book for the web; your browser and the DNS resolver just help you find the right number to go with the name. Just like your postal address allows people to address a letter to you, and your phone number allows people to direct phone calls to you, your IP address tells computers where to send things you are requesting. Once your browser has the correct IP address, it introduces itself (using your IP address) and “shakes hands” with the server at the other end. They exchange some pleasantries and reassure each other of their identities and…a connection is made!
So that’s it? I just connect to another server and look at whatever is there?
Close, but not quite. Making this connection, and the ensuing data exchange involves sending and receiving a series of Internet Protocol (IP) packets, which travel over the internet between your endpoint and wherever the responsive server is located. Sending packets over the internet is much like sending parcels through the mail. Each one is wrapped in a series of layers labeled with relevant information about the sender, receiver, and other information related to the shipping and handling of the packet. These layers are added by the sender’s computer, router, and modem, and then stripped by corresponding equipment on the receiving end. In between, the routing equipment in the ISP’s access network and other networks the packet traverses through use the information in the outermost packet header to send the packet towards its destination.
So, when you want to view a website on your computer, your browser asks the host server for the files of which the website is composed, including text, images, sounds, and video. That server then sends those files, broken up into a series of packets, to your IP address, where your modem translates them back into digital form and sends them to your router. The router determines which of your connected devices the packets are meant for (remember those private network addresses the router assigns to each device on your LAN?), then passes those packets on to your computer. Your computer will receive those packets and pass them to the correct application – in this case, your web browser – which will organize the content of the packets, assemble it into the elements of the webpage, and display it on your screen.
You mean everything I look at on the internet, er…I mean on the web over the internet, is transmitted directly into my computer? Who else knows about this?
So, that was an outline of the basic steps involved in accessing a website over the internet. Yes, everything you look at comes to your computer and all of that passes through the hands (not real hands) of one or more network operators. If this makes you uncomfortable, with so many different entities being able to see what you do online, you are not alone. On the bright side, many parts of the web now support encryption protocols, like HTTPS (look at the left-hand end of your browser’s address bar to check) which helps to keep prying eyes away from the content of your internet traffic. HTTPS encrypts only the actual content of packets, but not the packet header information, so most of the metadata (information about the packet’s size, destination, etc.) is still visible to network operators and others who may be monitoring internet traffic.
There are a few additional steps involved if you use a Virtual Private Network (VPN), which may add additional layers of encryption. A VPN will also hide your IP address from sites you visit and hide the identity of the sites you visit from your ISP. Although there are many reasons to use a VPN, enhanced privacy is an important benefit. If you’re interested in learning more about enhancing your privacy online, check out our posts about VPNs and DNS resolvers. For a more detailed look at IP packet structure and how it relates to online privacy, look at this post.
That all sounds a little scary. Isn’t there someone in charge of the internet?
In reality, no one is “in charge” of the entire internet. The individual networks are managed by the companies, governments, and municipalities that build and operate them. Most of these network operators choose to cooperate with other networks and many of their interactions and arrangements are conducted in private, giving us on the outside little opportunity to know or understand how inter-network relationships work. There are some international bodies that agree on standards and practices for network operation, while others work to ensure organization and consistency among the entities that connect to the internet. Many countries regulate either the practices of ISPs, the content and behavior of websites, or both, at least to some degree. A few countries exert more rigorous control over who can send traffic to their networks and what kinds of traffic are allowed. In our next post, we’ll talk about the concept of net neutrality and the various ways that the U.S. and others approach the idea.