Introduction to the Internet

Many people alive today can’t remember a time before the internet; it can be easy to forget how recently the internet was closer to science fiction than reality. In a little over forty years, the internet has evolved from a small network to an almost infinite source of information available around the world -- and even in outer space.

Internet History Milestones: 1969-1990

1969 - Launch of ARPANET

Military organization DARPA creates ARPANET, a small network of computers intended to share scientific research between a handful of universities and military organizations. More nodes (or computers) join the network over time, and ARPANET begins to grow.

1971 - The first email

Computer engineer Ray Tomlinson creates the first email software and sends the first message: a random string of letters.

1989 - Dawn of the World Wide Web

Computer scientist Sir Tim Berners-Lee explains a blueprint for the internet in his paper, “Information Management: A Proposal.” Between 1989 and 1990, he creates HTML, URI (or URL), and HTTP, three technologies that form the foundation of the internet we use today.

1990 - The first search engine

Eight years before Google, college student Alan Emtage creates Archie, the world’s first internet search engine. Archie makes it much easier to find specific files on the constantly-expanding internet. The same year, the world’s first website goes live. (Check it out!)


1993 - The Web goes worldwide

CERN makes its web source code public domain, or free for anyone to use. Now anyone who wants to learn can host a server or create a website. The user-friendly Mosaic web browser makes the internet more accessible to the average person. It’s one of the first browsers to support sound, video, and images alongside text.

1994 - World Wide Web standards

Sir Tim Berners-Lee founds the World Wide Web Consortium (W3C). Their mission: to make sure the web will be accessible to everyone. Agreeing on a set of universal “rules” helps web developers and tech manufacturers create products that are widely compatible.

1995-1997 - Social media goes mainstream

Web users reunite with old school friends online via Two years later, introduces user profiles, friend groups, and other features that will soon become standard. These early networks will pave the way for Facebook (2004), Twitter (2006), Instagram (2010), Snapchat (2011), and many others.

1999 - Wi-Fi as we know it

A group of important tech companies forms the Wireless Ethernet Compatibility Alliance. They have an important goal: standardizing wireless internet technology. And Wi-Fi is born.


2005 - The broadband revolution

In 2005, broadband (AKA high-speed internet) use surpasses dial-up internet usage for the first time. 33% of households in the USA have high-speed internet in the summer of 2005, while 28% still have dial-up. The discrepancy will continue to grow. By late 2016, 73% of households will have broadband internet access.

2008 - Internet in space

NASA successful tests internet in space via DTN (Disruption-Tolerant Networking) software. Unlike internet on Earth, DTN software won’t “time out” when a data request takes too long; instead, the data stays put until the connection opens up again. This makes DTN well-suited to handle disconnections, solar storms, and other complications.

2013 - Smartphones everywhere

For the first time, the majority of American adults (56%) own a smartphone, up from 35% just two years earlier. Among adults ages 25-34, smartphone ownership is closer to 81%.

2014 - Virtual reality on the horizon

Facebook buys rights to the virtual reality headset Oculus Rift for two billion dollars (that’s “billion” with a “b”). This huge investment shows where technology may be headed next: fully immersive digital worlds we’ll use for both work and play.

Internet MVP

No single person can take full credit for inventing the internet. The web evolved over many years, through the collective efforts of many people. So who can we thank for the likes of Google, Twitter and your favorite web-enabled tech? Here’s a lineup of influential internet innovators.

Leonard Kleinrock developed the mathematical theory behind packet-switching networks. Today, most internet protocols run on these technologies. He also played a vital role in establishing ARPANET, the precursor to today’s global internet. Fun fact: Kleinrock's own computer was the first device ever connected to the internet.

Larry Roberts was the principal director and designer of ARPANET. In 1966, the US Department of Defense asked Roberts to develop an experimental computer network. The goal of his mission was to send digital data from place to place. Though he was reluctant at first, Roberts embraced ownership of the ARPANET project. His work set the stage for the internet as we know it today.

Ray Tomlinson created email and saved the @ sign from extinction. He invented ARPANET's first electronic mail application, which allowed users to send messages to other computers. Tomlinson also set the familiar email address standard, user@host. This decision transformed a virtually obsolete character into one of the most important symbols on the keyboard.

Vint Cerf and Robert Kahn built the framework of the internet: the TCP/IP protocol. Though you might not recognize them, you use these protocols every day. TCP/IP communication standards paved the way for Wi-Fi, 4G, search engines, and more. Cerf and Kahn developed these standards decades ago, but they're still important today. Cerf himself described their invention as a "future-proof protocol".

Radia Perlman played a critical role in improving network protocols. The software engineer spent her early career designing algorithms and establishing standards to regulate communication between electronic devices. Essentially, these protocols function as traffic laws for how data should travel. Perlman’s clear rules reduced packet traffic jams, helping computers transfer data efficiently.

Tim Berners-Lee invented the World Wide Web. (Though they’re often used synonymously, the World Wide Web is just one part of the internet.)  Berners-Lee has worked tirelessly to ensure his invention is accessible to everyone. Today, he serves as director of the World Wide Web Consortium (W3C). This organization sets global standards to keep the web running.

Aaron Swartz advocated for universal accessibility of the internet. The programming prodigy developed standards with the WC3, campaigned against internet censorship bills and helped start Creative Commons, a nonprofit organization that makes online work shareable. Swartz's efforts have given countless users free access to digital resources.

Mark Zuckerberg made the internet social. In 2005, the Harvard student dropped out of school to focus on his start-up, Facebook. Now, it's the largest social media network in the world. Though Facebook wasn’t the first social platform to hit the interwebs, its 1.5 billion active users are a testament to its influence. The site’s ability to integrate with third-party apps set it apart from its predecessors.

Internet Glossary

Broadband internet

A high-speed internet connection that is “always on” and doesn’t require users to connect manually to their internet service provider (ISP), unlike dial-up internet.

Cloud computing

Accessing files that aren’t stored on your computer via an internet connection.


Digital information that has been converted into a format that is readable by machines, such as binary. Examples include text, images, and videos.

Dial-up internet

The earliest form of internet access, which requires users to “dial in” to a connection via a phone line.


An acronym for “HyperText Markup Language.” In code, HTML describes the overall structure of a webpage and tells a browser how text and images should be displayed.


An acronym for “HyperText Transfer Protocol.” This protocol, or set of rules, determines how files like text, images, videos, and more should be transmitted from servers to users.


A series of connected computers and other devices that share information.

Search engine

A set of programs that work together to make web pages searchable, create an index of available pages and return data that matches a user’s search terms.


A computer or program that fulfills requests by other programs or computers. For example, when you enter a URL into your address bar, the server associated with the site you’re trying to visit serves up the page you asked for.


A program that scans web pages to categorize them and make them readable by search engines. Also called a bot or a crawler.


An acronym for “Uniform Resource Locator.” A URL, also known as a web address, tells a server where to look for a specific file or webpage, using either an IP address or a domain name.

Key Concepts

The internet vs. the World Wide Web

The internet is a massive computer network made up of many smaller networks. The World Wide Web is a method used to tap into the internet -- navigating via URLs, viewing pages written in HTML (and other coding languages), and transmitting data via HTTP. There are ways to get online without accessing the Web; examples include instant messaging and email.

Software vs. hardware

Hardware is a physical device used with a computer or other device (like a mouse or keyboard). Software is a program or collection of programs designed to complete a certain task (like a browser, game, or operating system.) Software provides a set of rules and instructions, which tell your device what to do and how.

Dial-up vs. broadband internet

Dial-up, the earliest form of internet technology, requires users to manually “dial in” to a connection via a phone line each time they get online. A broadband connection, on the other hand, is “always on,” and offers much more speed than a dial-up connection can. Broadband internet is a category of high-speed internet technologies, including cable, satellite, DSL, and fiber optics.

Upload vs. download

When you share a file from your device to the internet or another device, that’s an upload. If you save a file to your device from another, that’s a download.

How does the internet work?

The internet isn’t just one thing—it’s a connected system of networks from all around the globe. Every internet connection, from the one you have at home to the giant servers at Google, plays a part.

In order to access content online, you have to send a request from your computer to the Domain Name Server (DNS). Routers help direct information up the chain, from network to network.

** Note: Protocols are rules that ensure all networks (big or small, near or far) can connect, communicate and send data. Ever wondered why we type http:// or www before every website name? It’s a way of making sure that all computers are speaking the same language. **

Let’s say you want to visit your favorite news site. When you type the website address ( into your browser, the request is sent from your computer to your Internet Service Provider’s servers. It keeps moving up the line until it reaches the Domain Name Server. The DNS is essentially a giant address book that matches the domain name you typed into the specific IP address of the server where that page is hosted.

**Note: The DNS is a lot like your phone’s contact list. Once you have your friend’s 10-digit phone number saved, you don’t need to remember it. You can type in their name and your phone handles the rest. In the same way, the DNS helps match a domain name ( to its corresponding series of numbers (like**

Once the site you’re looking for has been identified, its elements (pictures, videos, text and other files) are broken down into tiny pieces and sent back to you. Luckily, these data packets come with instructions for reassembly, so everything appears as it should when it loads on your computer screen.

Now that you have a working webpage displayed on your screen, you can navigate through the page. The process repeats every time you click a hyperlink or start a new Google search.