How the Internet Works Part II - Servers, Clients, and Protocols

The Infrastructure and Its Rules

If you haven't read part 1 of our series, check out How the Internet Works - Web Browsers and HTML!

In Part 1 of our series “How the Internet Works,” we discussed some fundamental processes of our internet experiences and came to the understanding that HTML, the language of the internet, is interpreted by our web browsers. The browser (Chrome, IE, etc.) reads this simple form of code and shows us the web page we feed through it. That leaves a question:

How do the web browsers get information from all over the world?

This article begins to answer that question by providing a basic understanding of the two primary components of the web - the infrastructure that supports it, and the rules that hardware follows as it passes information around the globe.

Components of the Web - Hardware and Protocols

The internet is essentially a vast network of linked computers governed by a set of codes that tell them what to do. The web is broken up into two primary components: hardware and protocols. The hardware is pretty straightforward - the computers, cables, and physical structures that enable the internet to work, including our mobile devices and desktop computers. The protocols - the rules and programs the internet uses - are a little more abstract. Before we learn how it all fits together in the next article of our series, let’s have a closer look at these components and their subdivisions.

Hardware - Servers to Clients

We need physical devices to both store and carry the information that makes up the internet. Each website is a file (or many files) containing information, and those files are stored in data banks. That information is transferred through the internet’s hardware system and then read through the browser on our devices. Those devices are broken into four primary forms of hardware:

1. Clients - the device that receives information from a source. That would be our computer, tablet, or smartphone.

2. Connections - the cables, wireless networks, and associated equipment that carries information to and from the clients.

3. Nodes - these guys are access points along the “highway” of connections - they direct information to and from clients and servers.

4. Servers - the source of the information we are looking for. Servers hold the information of websites, and send it to us - the client - via one or more connections.

So, servers hold information we want - the HTML, images, and other components of the website we are requesting. In order for us to get it, our client - computer, cell phone, tablet, etc. - sends a request to the server via the connections and nodes along the way. If one of these nodes or connections goes down, information can be rerouted through a different part of the web. That’s one of the reasons the internet is so powerful; we could feasibly lose a lot of our connections and still have full (albeit slower) access to all the information on the internet.

Just like our roads have rules, so does the internet. The rules of data transfer are called protocols, which govern how the 4 types of hardware interact.

Protocols - Laws of the Virtual Land

Protocols are harder to picture than the infrastructure of the web, but we don’t need an extensive knowledge of them to know what’s basically going on in our day to day interactions on the internet. Each of our devices has a particular fingerprint, called an Internet Protocol (IP) address. Servers and nodes have addresses as well - this is how the machinery knows where to find information.

The internet works in query-response fashion, meaning that our client sends a question to the next node or server on the ladder. If the node or server has the answer, it shoots it back - our browser then reads the code and paints it on our screen.

If, on the other hand, the next node or browser in the network doesn’t have the info - which is typically the case - it sends it further down the line towards a higher-level server. The process repeats over and over until the request finally hits the server with the right identifying protocol to answer the question. The server then sends the info back up the line to our client, and up pops whatever we were looking for.

Moving Forward

These components - hardware and protocols - form the backbone of the internet. Combined with our knowledge of HTML and the purpose of a web browser that we learned in our first article, we are ready to put it all together to see exactly how the internet works.

Click here for the conclusion of this part of our series: How the Internet Works Part III

Remember to check out the links below for more cool information!