How The Internet Works (in a Nutshell)
Basic Network Picture
The Internet Explained
Have you ever wondered about how the internet actually works, but don't have a great deal of technical knowledge? No problem, you've come to the right place. I will attempt to explain the basics of how the internet works without getting too technical. To do so, we will step through the network diagram above. But first, it's important to understand the following three points.
First of all, it is important to understand that the internet is nothing more than a term used to describe a massive world wide network of computers connected together for the purpose of sharing content. Every computer or network device connected to the internet has two things true about it, a physical connection is established via a physical cable or a wireless device and it has software necessary to interpret/send/receive the various internet protocols. The protocol refers to the way in which data is transferred from one device to the next. For instance, web page viewing uses a different protocol than sending email. Fortunately, software does all of this automatically for us, so we don't need to understand the underlying technology. But, we do need to understand the high level basics of what is going on.
Another thing to understand is that viewing websites may be what most people think about when they think of the internet, but it's not the only thing to do on the internet. However, since it's the most common thing to do, that's what we'll discuss here. It's also important to understand here that a webpage is nothing more than a collection of text files, stored somewhere on a web server. We'll talk more about that later.
The final point is that in order to understand the basics of the internet you really have to understand the basics of a computer network, because that's really all the internet is.
Important Terminology Referenced in This Article
LAN -Local Area Network - A localized internal collection of devices all connected together inside one home or one building of an organization.
Internet - or World Wide Web - The collection and connection of all internal networks together to form one huge world wide network for sharing information across all homes and organizations connected.
Switches/Routers/Modems/Wireless Access Points - Devices on a computer network that perform various functions related to physically connecting computers together and routing traffic in between one computer and another.
IP Address - Internet Protocol Address - A unique set of numbers assigned to every single device on a network that functions much like a street address on a house. It lets every other device on the network know where to find the device assigned that number.
Server - A powerful computer that is used to serve some function on a computer network. Servers perform various functions, such as hosting web pages, hosting network printers, hosting file shares, handing out IP address, and much more.
DNS - Domain Name Service - A service, typically running from a server that matches and translates names to IP addresses.
DHCP - Dynamic Host Configuration Protocol - A service, typically running from a server that assigns each network device its own unique IP address.
Web Browser - A piece of software used to access websites. The most common browsers include IE (Internet Explorer), Chrome, Firefox, and Safari.
URL - Uniform Resource Locator - Name used to point to a website. This is what you type in to get to a website or what pops up when you search for a website. A URL looks something like "www.website.com".
Understanding What Happens When a Website is Opened
We will now step through what happens when someone opens a website in order to get a conceptual view of how the internet works. You can use the network diagram above for a pictorial reference.
1. The end user opens a web browser and types in a URL, which is the name of the website they are wanting to see.
2. The URL request is sent through their LAN to their internet service provider.
3. The internet service provider then sends the URL requested to an external DNS server, which is either hosted by them or by who ever provides their internet access.
4. The external DNS server then matches the URL up with the external IP Address assigned to the LAN hosting that website and the request is then sent on to that network.
5. The network hosting that website accepts the request and then sends it to its own internal DNS server.
6. The internal DNS server matches the URL requested to the internal IP address of the actual web server where the files making up the website are physically stored.
7. The request is then sent to the web server and the web server packages up the files that make up the website requested.
8. The website that is all packaged up now makes the return trip in reverse all the way back to the computer that originally made the request.
9. The web browser on that computer then interprets the text files full of computer code sent to it by the web server hosting the site and displays them as a graphic website.
This is a high level overview of how the internet works and each of these main steps can be broken down into hundreds of sub steps. But, that would get much too technical for this particular explanation.