How Does the Internet Work: A Step-by-Step Pictorial

Tech Takes - May 24, 2019

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The internet plays a significant role in our daily lives

In the year 2000, only 52% of US adults used the internet [1]
In 2018, that number jumped to 89%
In 2013, US adults who didn’t use broadband internet at home but owned smartphones was just 8%
In 2018, that number increased to 20%

As you’re reading this article, you’re contributing to history. Over the last fifty years, technology and the functionality of the internet have transformed to become the convenient systems we use in our daily lives.

But as you might have guessed, the internet didn’t always look this way, nor was it so popular. In fact, in the year 2000, only 52% of US adults said they used the internet; but in 2018, that number jumped to 82% [1].

From the query that got you here in the first place: “how does the internet work?” to shopping online and communicating with family and friends, the internet has completely changed the way we live, collaborate, and learn. But where did this all get started? And how did the internet evolve into the ubiquitous system we know it as today?

To fully understand how the internet works and how we got here, we’ll need to start from the beginning.

A Brief History of the Internet

On October 29, 1969, an organization called ARPANET (Advanced Research Projects Agency) launched the first iteration of the internet (also known as ARPANET) connecting four major computers at The University of Utah, UCSB, UCLA, and Stanford Research Institute [2].

When this network of computers was connected, universities were able to access files and transmit information from one organization to the other, as well as internally.

As researchers developed the system, they continued to connect computers from other universities, including MIT, Harvard, and Carnegie Mellon. Eventually, ARPANET was renamed “internet.”

Who used the internet in this stage?

In its earliest days, the internet was only used by computer experts, scientists, engineers, and librarians who had to learn a complicated system in order to use it, but as the technology improved and consumers adapted, it became an essential tool for people around the globe.

How and when did the functionality of the internet change?

The 1970s was a serious time of transition for the internet. Email was introduced in 1972, libraries across the country were linked, and above all, information exchange became more seamless thanks to Transport Control Protocol and Internet Protocol (TCP/IP) architecture.

The invention of these protocols helped to standardize how information was sent and received over the web, making the delivery more consistent, regardless of where or how you’re accessing the internet.

When did the internet become user-friendly?

Then in 1986, the National Science Foundation took the development of the internet to the next echelon by funding NSFNET, a network of supercomputers throughout the country.

These supercomputers laid the groundwork for personal computing, bridging the gap between computers being used exclusively for academic purposes and computers used to perform daily tasks.

In 1991, The University of Minnesota developed the first user-friendly internet interface, making it easier to access campus files and information. The University of Nevada at Reno continued to develop this usable interface, introducing searchable functions and indexing.

When did consumers begin using the internet?

As the internet’s development continued to evolve and shift focus, the National Science Foundation discontinued its sponsorship of the internet’s backbone (NSFNET) in May of 1995.

This change lifted all commercial use limitations on the internet and ultimately, allowed the internet to diversify and grow rapidly. Shortly after, AOL, CompuServe, and Prodigy joined Delphi to offer commercial internet service to consumers.

The debut of WiFi and Windows 98 in the late nineties marked the tech industry’s commitment to developing the commercial element of the internet. This next step gave companies like Microsoft access to a new audience, consumers (like yourself).

What does internet usage look like today?

Flash-forward to today. It’s estimated that three billion people now use the internet, many of whom use it on a daily basis to help them get from Point A to Point B, catch up with loved ones, collaborate at work, or to learn more about important questions like how does the internet work? [3]

As technology changes and the internet weaves its way into just about every aspect of our lives, even more people are expected to use it. In 2030, researchers project there will be 7.5 billion internet users and 500 billion devices connected to the internet [4].

How does the internet work?

Now that you have some background on the evolution of the internet, let’s tackle the question at hand: “how does the internet work?”

The internet is a worldwide computer network that transmits a variety of data and media across interconnected devices. It works by using a packet routing network that follows Internet Protocol (IP) and Transport Control Protocol (TCP) [5].

TCP and IP work together to ensure that data transmission across the internet is consistent and reliable, no matter which device you’re using or where you’re using it.

When data is transferred over the internet, it’s delivered in messages and packets. Data sent over the internet is called a message, but before messages get sent, they’re broken up into tinier parts called packets.

These messages and packets travel from one source to the next using Internet Protocol (IP) and Transport Control Protocol (TCP). IP is a system of rules that govern how information is sent from one computer to another computer over an internet connection.

Using a numerical address (IP Address) the IP system receives further instructions on how the data should be transferred.

The Transport Control Protocol (TCP) works with IP to ensure transfer of data is dependable and reliable. This helps to make sure that no packets are lost, packets are reassembled in proper sequence, and there’s no delay negatively affecting the data quality.

Wondering how the internet works from browser launch to search results? Let’s go over the process step-by-step [7] [8] [9].

When you type in a web address into your browser...

Step 1: Your PC or device is connected to the web through a modem or router. Together, these devices allow you to connect to other networks around the globe [6].

Your router enables multiple computers to join the same network while a modem connects to your ISP (Internet Service Provider) which provides you with either cable or DSL internet.

Step 2: Type in a web address, known as a URL (Uniform Resource Locator). Each website has its own unique URL that signals to your ISP where you want to go.

Step 3: Your query is pushed to your ISP which connects to several servers which store and send data like a NAP Server (Network Access Protection) and a DNS (Domain Name Server).

Next, your browser looks up the IP address for the domain name you typed into your search engine through DNS. DNS then translates the text-based domain name you type into the browser into the number-based IP address.

Example: Google.com becomes 64.233.191.255

Step 4: Your browser sends a Hypertext Transfer Protocol (HTTP) request to the target server to send a copy of the website to the client using TCP/IP.

Step 5: The server then approves request and sends a “200 OK” message to your computer. Then, the server sends website files to the browser in the form of data packets.

Step 6: As your browser reassembles the data packets, the website loads allowing you to learn, shop, browse, and engage.

Step 7: Enjoy your search results!

The future of the internet

Whether you’re searching for information on how the internet works, streaming your favorite movie, or browsing the internet for travel deals, it’s undeniable that the internet takes us places, and it’s going to continue to do so!

While it might not seem like the internet is changing now, chances are, we’ll look back and see how far we’ve come, the differences in how we use this technology, and ultimately, we’ll find that we, too, are a part of the internet’s history.

[1] Pew Internet; Internet/Broadband Fact Sheet

[2] Walt Howe; A Brief History of the Internet

[3] Money; Here's How Many Internet Users There Are

[4] Cisco; Internet of Things

[5] Lifewire; TCP (Transmission Control Protocol) Explained

[6] Mozilla; How the Web works

[7] How Stuff Works; How does the Internet work?

[8] How to Geek; How Does the Internet Work?

[9] Medium, How Does The Internet Work

A brief history of the internet

Philosophers and authors have conceptualized a shared repository of world knowledge for centuries. How did we get to the internet we know today?

Major breakthroughs [2]

October 29, 1969: ARPANET (later renamed internet) created a successful connection between University of California Los Angeles and the Stanford Research Institute.

Late 1960s: Libraries automate and network catalogs independent of ARPANET.

1970s: Transport Control Protocol and Internet Protocol (TCP/IP) is established, allowing for internet technology to mature. The invention of these protocols helped to standardize how information was sent and received over the web.

1986: National Science Foundation funded NSFNET, which is the 56 Kbps backbone of the internet. There were commercial restrictions in place at this time because federal funds were being used to run and maintain it.

1991: User-friendly internet interface was created.

July 1992: Delphi became the first national commercial online service to offer internet access.

May 1995: All commercial use limitations on the internet disappear. This allowed the internet to diversify and grow rapidly.

1997: WiFi was invented.

1998: Windows 98 hit the market.

2007: Widespread smartphone adoption.

2009: 4G network is introduced.

Today: 3 billion people use the internet. [3]

2030: 7.5 billion projected internet users and 500 billion devices connected to the internet. [4]

How does the internet work?

Messages + Packets

Data sent over the internet is called a message
Before messages get sent, they’re broken up into tiny parts called packets

Internet Protocol (IP)

Rules that govern how information is sent from one computer to another computer over an internet connection
Specifies how computers should send information to other computers by sending data with an attached numerical address (IP Address)
- Public IP Address: Accessible over the internet
- Private IP Address: Assigned to a device on a closed network such as a home or business network that’s not accessible over the internet

Transport Control Protocol (TCP)

Works with IP to ensure transfer of data is dependable and reliable
No packets lost, no delay negatively affecting data quality, packets reassembled in proper sequence

What happens when you surf the internet...

Step 1: Your PC or device is connected to the web through a modem or router, which allows it to connect to other networks around the globe. [6]

A router allows for multiple computers to join the same network while a modem connects to your Internet Service Provider (ISP) which provides either cable or DSL internet.

Your personal PC is called a client as opposed to a server.

Client computers connect to the internet through an ISP.
- Example: Your phone connected to a mobile network or your laptop connected to WiFi.
Servers are computers directly connected to the internet.
- Example: Computers that store web pages, sites, or applications.

Step 2: Type in a web address, known as a URL. URL stands for Uniform Resource Locator.

Step 3: Your query is processed and pushed to your ISP. Your ISP has multiple servers which store and send data like a NAP Server (Network Access Protection) and a DNS (Domain Name Server).

Your browser looks up the IP address for the domain name you typed into your browser through DNS.

DNS translates the text-based domain name you type into the browser into the number-based IP address.
- Example: Google.com becomes 64.233.191.255

Step 4: Browser sends a Hypertext Transfer Protocol (HTTP) request to the target server to send a copy of the website to the client using TCP/IP.

HTTP: Language used for internet communication.
HTTPS: Secure version of HTTP, all communications between your browser and website are encrypted.

Step 5: Server approves request and sends a “200 OK” message to client computer. Then, the server sends web page files to browser in the form of data packets.

Step 6: Web page loads as your browser reassembles packets.

Step 7: Enjoy browsing the internet! [7] [8] [9]