The Internet is a global network of billions of computers and other electronic devices.
This works through a series of networks, servers, and devices that connect around the world through telephone lines and satellites, also known as the network of networks. This network has no center - even though it did start somewhere, if that center were to go offline, the internet would continue unimpeded. The only thing that would threaten the internet as we know it is if all the ISPs were to collapse at the same time (which is unlikely).
The internet works like this - the Federal Communications Commission (FCC) controls and regulates internet service providers (ISPs). ISPs have helped pay for and build telephone and fiber wiring infrastructure between servers, ISPs, and your home. These wirings make up the internet - when you buy from an ISP, you're paying for access to the internet, not necessarily the internet itself. Your ISP will usually give you a router and a modem - the router is to connect to the phone lines and along with it, the internet. The modem is to wirelessly connect your devices to the router. When you attach your computer to the internet via a wire from your router or modem, this is known as Ethernet. When you use Ethernet to gain access to the web, your computer is connecting to the Local Area Network (LAN). When using a wireless connection, you're using the Wireless Local Area Network (WLAN).
Internet (which comes from the concept of "inter"connecting "net"works) emerged in the United States but did not become visible to the general public until the early 1990s, with its first trial version being run by the Advanced Research Projects Agency (ARPANET) and Defense Data Network of the U.S. Department of Defense in the 1980s. The National Science Foundation (NSF) created the first high-speed backbone (aka the first line-connected network) in 1987. Called NSFNET, it was a line that connected 170 smaller networks together. Today there are many companies that operate their own high-capacity backbones, which are all interconnected via phone lines and satellites. Everyone on the Internet, no matter where they are and what company they use, is able to talk to everyone else on the planet. The entire Internet is a gigantic, sprawling agreement between companies to intercommunicate freely.
While the Internet is theoretically decentralized (controlled by no single entity), many argue that tech companies such as Amazon, Facebook, and Google represent a small group of organizations that have unprecedented influence over the information and money on the Internet. Not to mention the birthplace of the internet was deeply rooted in surveillance before it became a tool for the general public, beginning as a tool for the U.S. Department of Defense to communicate quickly with other sectors in case of war.
The World Wide Web—usually called the Web for short—is a collection of different websites you can access through the Internet. The network of connected computers that the web works on (the Internet), as well as what emails and files travel across, act as roads to connect towns and cities together. The world wide web contains the things you see on the roads like houses and shops.
URL stands for Uniform Resource Locator. A URL, also known as a domain name, is nothing more than the address of a given unique resource on the Web. When you look at a website, the URL is displayed at the top, along with the page's title in the tab (https://www.spacehey.com/ is considered a URL). The letters at the tail end of a web address are called a domain extension or top-level domain (TLD), and there are around 1,500 possibilities.
If you look at any domain name, you’ll see a series of words, letters, or numbers connected by dots. For example, the blogging section of SpaceHey is located at blog.spacehey.com – three words separated by two dots. Each “dot” represents a different segment and helps computers (like a web browser) find the proper content. Furthermore, each segment is a different “level”. You start at the top-level (hence TLD) and move up in numbers.
For example, going back to the URL example above, you'd get:
- .com – top-level
- .spacehey – second-level
- blog – third-level, also called the subdomain in this case
Think of the parts of a domain name as classification levels. At the top, we have domain extensions. At this level, domains are divided into broad categories. For example, the domain extension .de puts the domain in the “German” category. Using .gov means the domain is in the “American governmental organization” category. Domain extensions aren’t always used this way anymore (like in the instances of .xyz or .pizza) but it was the original intention.
The next level down is the domain. That’s the part right before the extension. It designates which website the URL belongs to. In this case, it would be spacehey. Sometimes there’s another level called a subdomain. Subdomains organize a website into separate parts.
The web has to be able to translate domains to their own IP addresses as well - the act of changing a domain to an IP Address is handled through the Domain Name System (DNS).
The Hypertext Transfer Protocol (HTTP) is used to load webpages using hypertext links. It is the foundation of any data exchange on the Web and it is a client-server protocol, which means requests are initiated by the recipient, usually the Web browser, through a user-input. For example, typing in a URL into a web browser causes a browser to "fetch" the web domain you're looking for. A complete document is reconstructed from the different sub-documents fetched (ie. text, layout description, images, videos, scripts, etc.).
(Pictured: An example of an HTTP fetch request.)
In today's world, you'll see less and less websites using HTTP, and for good reason. HTTP has a flaw in which it is unsecure in a modern setting - it is not encrypted and thus is vulnerable to middle-man and eavesdropping attacks, which can let attackers gain access to website accounts and sensitive information, and modify webpages to inject malware or advertisements.
Hypertext Transfer Protocol Secure (HTTPS) is a secure version of the HTTP protocol that uses the Secure Sockets Layer (SSL) or its successor, Transport Layer Security (TLS) protocols for encryption and authentication. SSL has been since retired but it's still referred to as an SSL/TLS protocol. These two names are used interchangeably for TLS encryptions and certificates because of an issue with the original brand that created it. That and SSL has name recognition.
(Pictured: HTTP vs HTTPS, demonstrating the connections between a user and the websites.)
SSL can only be implemented by websites that have an SSL certificate (technically a TLS certificate). An SSL certificate is like an ID card or a badge that proves someone is who they say they are. SSL certificates are stored and displayed on the Web by a website's or application's server.
Let's talk more about the things you'll see inside the internet.
When you open your browser, it will open to the Home Page. The home page can be set to any URL you'd like - but when you first open up a browser, it'll just be the browser's dedicated home page. Any time you close and open a browser window, it'll go back to your home page. A lot of browsers also have a home button, which will also take you home. We'll go over more parts of the browser in the "Browsers, servers, extensions, oh my!" Lesson.
A hyperlink is a clickable item that will take you to another URL, like this link that leads to my Table of Contents. These can be present on images, navigation bars, advertisements, and more. Hyperlinks come in many different forms which can make it hard to know when they're even present. However, you can always identify a hyperlink by moving your mouse cursor over the item. If the bottom left corner displays a URL, then you know it's a hyperlink! This is called hovering and it's also useful for checking that links will go to where they say they do. Links you receive in your email or messages can be checked this way for scams.
Sometimes hyperlinks will initiate a download, which is the transfer of data to your computer over the web. When you transfer data out from your computer to the web, that's called an upload. Downloads and uploads are effected by the bandwidth, or the measurement of the volume of data that can be transmitted over a network at a given time. Usually, this is measured in bits per second. Your bandwidth also has an impact on how well your machine will load parts of the web that it's trying to fetch, because the lower your bits per second is, the less data that can funnel through your network to your browser.
Now that we know a little more about the internet, let's learn more about your window into the web - your browser!