How Does the Internet Work? A Simple Explanation of the Internet

Undoubtedly, if you're reading this article, you're familiar with the internet. You've seen how it's changed your life - enabling instant communication and putting a world of information at your fingertips. But have you ever wondered how it all works? In this article, we give a simple explanation of how the internet works.

First, Some Network Basics

Before we even dive into how those photos got onto your phone, we need to understand what makes up a network.

Networks are groups of interconnected devices. Any device that is connected to a network is known as a "node." Most modern networks contain the following nodes:

1. Network Interface Cards / Network Adapters
2. Switches
3. Router
4. Wireless Access Point

1. Network Interface Cards

Also known as Network Adapters, Network Interface Cards are the hardware that's installed in computers, such as your laptop or PC. Though not a node themselves, they allow computers and electronic devices to join a network as a node.

2. Switches

Network switches are central nodes that forward messages between nodes in the same network by rapidly creating and deleting connection points. You can think of them as the managers of the network, maintaining the flow of information between the devices in a network, whether wireless or wired.

3. Router

A network router is a device that connects two or more separate networks. Routers forward data to other routers of different networks until the data has reached its destination.

4. Wireless Access Points

WAPs allow nearby computers and nodes to interact with a network wirelessly, usually via WiFi. They're nodes that provide wireless capability to a wired network.

Multiple WAPs can be connected to extend the wireless capability range of a network, such as in a large building. However, WAPs aren't a required component of a network, as networks can remain completely hardwired.

Quick Note: WiFi Connection vs. Internet Connection

Contrary to popular belief, WiFi doesn't have anything to do with your internet connection and the two terms shouldn't be used interchangeably, although they often are.

WiFi only applies to the strength of your connection to a Wireless Access Point (WAP) Located in your Local Area Network (LAN). Internet connection measures the strength of your router’s connection to the internet. You can have a strong connection to your WiFi, but no connection to the internet and vice versa.

Here are another 8 things you didn't know about WiFi.

The Birth of the Internet

The origin of the internet began in the late 1960s and early 1970s from a new network technology created by the U.S. Department of Defense. It was known as the Advanced Research Projects Agency Network (ARPANET).

Its purpose was to connect various Department of Defense scientists and researchers across the United States working on defense projects. Researchers incorporated ARPANET into the networks they were working at including universities. As more and more networks joined the system, the internet began to take shape.

So, What Is the Internet?

In basic terms, the internet is a global interconnected collection of networks that communicate using internet protocols (wait, how do protocols work?). You can think of it as a network of networks where every network is a node.

However, new devices and technologies have created new ways to connect to networks through the internet. A combination of them is often used to make these connections.

1. Wired Internet

This is the most common form of connection to the internet. Hundreds of thousands of miles of wires are laid throughout the world. They range from phone lines (DSL) to fiber optic cables.

Data can travel up to 70 percent the speed of light through ideal wire mediums such as fiber optic cables, which allow extremely fast transfer of data.

Many of these wires are laid underground or underwater to prevent degrading. On land, along with being underground, they're also placed with utility lines that travel along roads.

Single lines can span thousands of miles, such as the underwater transatlantic communications cables that connect various parts of the U.S and Canada to Europe. This is the ideal and fastest way to access the internet.

2. Satellite Internet

People who have satellite dishes on their roofs are connecting to the internet via satellite. This is usually required when there are no wired connections available in the local area to connect to the internet, such as third world countries and areas with low populations.

Though satellite is relatively fast, it's still slightly slower than wired connections due to longer transmission distances (up and back down instead of across). Also, if the final address for the data isn't within range of the satellite (like sending that email to your parents), the data needs to pass from satellite to satellite until it arrives at one that is within range.

3. Cellular Internet

A relatively recent addition, cell phones have joined the internet. Cell phones connect using cell towers, which then connect to physical wires and to the rest of the internet.

In a sense, cell towers are sort of like extremely wide Wireless Access Points, except they're only for cell phones or data-enabled devices. Cell phones may also act as wireless routers using mobile hotspots, in which a laptop or similar device could connect using WiFi to access the internet.

Ok now about those emails you received...

How Does the Internet Work?

When you opened your email, your email application sent a request to your email provider (for example, Gmail) through your laptop’s Network Interface Card to your Wireless Access Point (WAP) using your local WiFi. The WAP then sent the request through a wire to the local router.

The local router took that request and sent it to another router, which then sent to another router, and another router, all the way through a chain of routers until the data was transferred over one of the transatlantic communication cables to the United States.

There, it ended up at a Google data center (because you use Gmail). Google then processed your request to get any new emails that had come in since you last loaded your email. They packaged up your new, unread emails in a digital package called a "response," and sent that package back to the same address (your laptop) that requested the updates. The response probably took different routes on the way back, but it went through the same mechanisms.

The data was transferred from the Google data center through multiple lines and reached your home router/modem, which made the data available over your home WiFi. Your laptop's Network Interface Card received the response, sent it to your email application, and then voilà—your new emails fill up your inbox!

And that all happened in the blink of an eye. It's pretty amazing how the internet works, isn't it? So the next time someone asks, "what is the internet" or "how does the internet work?" hopefully you can use this simple explanation to help them understand how this technology that's so important to our modern daily life actually works.

Originally published June 28, 2017. Updated January 29, 2020.