NYC Digital Safety

Internet Technologies

Many of us use the internet everyday. We use it to connect and communicate, to learn, to work, to shop or bank, or just browse cat videos. We may be required to use the internet to access government services, or to search and apply for jobs.

It can be hard to feel like we have control of our online lives when we don’t understand how our personal information is moving around the internet. This module provides a basic understanding of internet technologies. We’ll start at the very beginning, by building a working definition of the internet.

One way to describe or understand something as big and intangible as the internet is by using metaphor. Pause the video for a moment to consider all the metaphors you’ve heard to describe the internet or how we use it. One familiar metaphor for web use, for example, is “surfing,” as in surfing the web.

People have described the internet as a series of “tubes,” “an information superhighway,” “a web.” They might talk about technologies that “crawl the web” or, as we mentioned, when we browse we might say we “surf the web.” These metaphors bring to mind connections, interconnections, something that’s spread out, distributed or decentralized with movement or flow of information.

The internet is an interconnected network of networks of devices (such as computers, smartphones, and other computing devices), which are sending and receiving information via a shared protocol. Let’s unpack this definition, and define some key concepts.

The internet is a network of networks. Anytime two or more computers are connected, you have a network. All the computers in each library are connected, and can communicate with each other on a local area network, or LAN. The LAN at your library is networked with thousands and thousands of other LANs near and far, even though those other networks are owned and managed by other libraries, schools, businesses, governments. These other networks may be located on the other side of the world.

We sometimes use the term “world wide web” or “web” interchangeably with “internet” but they are different ideas. The internet is the physical infrastructure for communication, and the web is the system of content — such as web pages, words, images, data, puppy videos — all connected by hyperlinks, that is stored, sent and received on the internet.

What makes all this sending and receiving possible on the internet is a set of what we call shared protocols. Protocols are an agreed upon, standard method of communication that all devices use, whether they’re connecting from New York, Nairobi, or Nagoya. In this way, any device is able to communicate with any other device in the internet. One such protocol is called hypertext transfer protocol, or HTTP, or the secure version known as HTTPS. This probably sounds familiar to you: it’s the prefix on any web address. It acts kind of like a salutation or greeting, to announce a device is using the correct protocol.

HTTP (or hypertext transfer protocol) is the prescribed method that clients and servers use to share information. Clients send requests and servers respond, either with the requested information, or with an error code, like 404: File Not Found. Information is sent as plain text, and unless a secure protocol is used, can be read by anyone!

As we’ve seen, the internet is an network of interconnected networks.

Net neutrality, which is a laws that was in effect in the United States until 2017, ensured that everything by default was sent as readable text, in the open, across many networks controlled by many different actors. It’s what makes the internet reliable, and it’s also why there are so many data security challenges online.

The process of encryption — encoding data so it’s unreadable except to those with authorization — is critical in keeping the internet safe.

While the way information is structured and sent online is still open, how freely that information may flow through networks controlled by different actors changed in 2017.

Net Neutrality laws were rolled back, allowing network owners to charge users more for access to certain kinds of content (such as streaming video), and slow the speed of online communications in order to increase profits. See the resource list for more on this important issue.

The Online Information Flow

Let’s take what we’ve learned so far about internet devices and protocols, and reconstruct the path of a single request from one of the library’s public computers to a web server and back. We’ll imagine that a library user has logged on to a library computer to read the New York Times.

Step 1: The HTTPS request. On a library computer, a patron types “nytimes.com” into the browser bar and hits enter.

The browser is a piece of software on the computer that lets you visit webpages and use web applications.

The request is sent to the library’s router. Information that travels across the web is divided into smaller “chunks” of information known as “packets.” We’ll hear more about packets in a few moments.

Step 2: For systems in which signals need to be converted — like those using telephone lines — the modem converts data into the format that can travel along the Internet Service Provider’s cables.

Step 3: At the Internet Service Provider — the ISP — a domain name server translates the human-readable URL to the numerical addresses needed for locating and identifying resources on the web.

Step 4: The ISP’s routers determine the best and quickest path this packet can take to the address in the request.

The request may be routed through many other networks as it makes its way to nytimes.com. And, depending on where the nytimes.com server is located, the request may travel cross country or along fiber optic cables under the oceans.

Step 5: The request is received by the server.

Servers are computers that store and “serve” up content (like web pages) in response to HTTP requests.

Success! The information requested is available, so the patron is sent a response with all the data and code for a web page (and not an error message).

Step 6: The information (including text, images, videos) the patron requested from nytimes.com is too big for just one packet.

So all the material is broken down into multiple packets, to be reassembled at the end of its journey.

Step 7: The packets are addressed to the patron’s computer, routed along a path to the patron,
converted back into a browser-readable information, and assembled and displayed by the patron’s computer so the patron can view them. Packets can find their way back to the patron’s computer along any number of routes, and this is determined by networking protocols.

You now know how information flows through the complex system that is the Internet, in many forms, across many devices, through many networks to its destination.