The internet began in 1969 as a military experiment, not as a public network
The internet started as ARPANET, a project funded by the U.S. Department of Defense's Advanced Research Projects Agency (ARPA). On September 2, 1969, the first message traveled between two computers: one at UCLA in Los Angeles and one at Stanford Research Institute in Palo Alto, California. The message was meant to be "LOGIN," but the system crashed after the first two letters, so the first internet transmission was actually "LO."
ARPANET was designed to let military researchers share computing power and data across distances. At the time, computers were enormous machines that cost hundreds of thousands of dollars. If a researcher needed to use a computer at another institution, they had to travel or mail physical punch cards. ARPANET solved that problem by connecting computers through telephone lines, letting scientists work remotely.
The network grew slowly. By 1971, there were 15 computers connected to ARPANET. By 1977, there were 111. These were not personal computers — they were mainframes and minicomputers at universities and research centers. Nobody outside these institutions could access the network.
Key Takeaways
- ARPANET, created in 1969 by the U.S. Department of Defense, was the first network to connect computers across distances using telephone lines.
- The internet as a public system did not exist until the 1990s, when the World Wide Web and commercial internet service providers made it accessible to ordinary people.
- TCP/IP, the set of rules that computers use to talk to each other, was developed in the 1970s and became the standard that made different networks compatible.
- The web browser and the ability to view pages with text and images transformed the internet from a text-based tool for researchers into something the general public could use.
How ARPANET became the internet through a common language
ARPANET worked, but it had a problem: it was not the only computer network. Universities built their own networks. Companies built their own networks. These networks could not talk to each other because they used different rules for how computers should communicate.
In the mid-1970s, computer scientists Vint Cerf and Bob Kahn developed TCP/IP — a set of rules (called a protocol) that any network could use to send data to any other network. TCP/IP did not care what kind of computer you had or what network you were on. If your computer spoke TCP/IP, it could reach any other computer that spoke TCP/IP.
ARPANET switched to TCP/IP in 1983. Other networks adopted it too. Suddenly, all these separate networks could connect to each other. That moment — when many networks became one interconnected system — is when ARPANET became the internet.
For the next decade, the internet remained a tool for researchers, universities, and the military. Most people had never heard of it. The computers that ran it were still expensive and hard to use. You needed to know command-line instructions — text commands you typed rather than buttons you clicked.
The World Wide Web made the internet something ordinary people could use
In 1989, Tim Berners-Lee, a physicist working at CERN (a research laboratory in Switzerland), invented the World Wide Web. This was not the same as the internet. The internet was the network — the pipes and the rules for sending data. The web was a system for organizing and displaying information on top of that network.
Berners-Lee created three things: HTML (a language for writing pages), HTTP (a protocol for requesting and sending pages), and the first web browser (software that could display those pages). In 1991, he put the first website online. It was a straightforward page with text and links to other pages.
The web was revolutionary because it was straightforward. You did not need to know command-line instructions. You could click a link and jump to another page. Pages could contain images, not just text. Anyone could create a website without being a programmer.
In 1993, Marc Andreessen and Eric Bina at the University of Illinois created Mosaic, the first web browser that ordinary people could actually use. It displayed images inline with text, had a straightforward point-and-click interface, and worked on personal computers. Mosaic made the web accessible to non-technical people.
Commercial internet service providers opened the network to the public
For most of the 1980s, the internet was restricted to government, military, and academic use. Commercial use was not allowed. That changed in 1991 when the National Science Foundation lifted the restrictions.
Companies began offering internet service provider (ISP) accounts to the public. In 1995, AOL (America Online) became the largest ISP, with millions of subscribers connecting through dial-up modems over telephone lines. CompuServe and Prodigy were other major providers. These companies charged monthly fees — typically $20 to $30 — for unlimited internet access.
Dial-up was slow by today's standards. A 56k modem (the fastest available in the late 1990s) could read about 7 kilobytes per second. A single photograph might take 30 seconds to load. But it was fast enough for email, text-based websites, and straightforward graphics.
By 1995, the internet had become a consumer product. Websites began appearing for newspapers, retailers, and entertainment companies. People started using email instead of postal mail. The internet went from a specialized tool for researchers to something millions of people used every day.
The internet continued to grow as connection speeds increased
Dial-up was the dominant way people connected to the internet through the late 1990s and early 2000s. But faster technologies were being developed. Cable modems, which used the same lines that carried television signals, could read at 1 to 10 megabytes per second — 100 times faster than dial-up.
DSL (Digital Subscriber Line) used telephone lines but with different technology than dial-up, reaching similar speeds to cable. By the mid-2000s, cable and DSL had replaced dial-up for most home users. Websites could now include video, music, and complex graphics.
Mobile internet arrived with smartphones. The iPhone, released in 2007, put a web browser in people's pockets. 4G networks in the 2010s made mobile internet fast enough for streaming video. Today, 5G networks are rolling out with speeds comparable to home broadband.
The infrastructure that carries internet data has also changed. In the early days, data traveled through telephone lines. Today, most long-distance internet traffic travels through fiber-optic cables — thin strands of glass that carry data as pulses of light. Undersea cables connect continents. Satellites are beginning to provide internet to remote areas.
The internet today is vastly larger than anyone predicted in 1969
When ARPANET was created, nobody imagined billions of people would use it. The first computers on the network could store a few megabytes of data. Today, data centers store petabytes — millions of times more.
The internet has become the backbone of modern life. Banks use it to transfer money. Hospitals use it to share patient records. Stores use it to sell goods. People use it to work, learn, communicate, and entertain themselves. The COVID-19 pandemic in 2020 showed how dependent society had become on internet connectivity — schools, offices, and businesses shifted online almost overnight.
The internet is no longer something you "go on" by connecting a modem. It is always on. Your phone, your car, your refrigerator, your security camera, and your smart speaker are all connected to the internet. This is called the Internet of Things — the network of physical devices that communicate with each other and with servers.
The basic technology has remained the same since 1983: computers send data to each other using TCP/IP. But the speed, scale, and reach of that network have transformed beyond recognition.
Frequently Asked Questions
Who actually invented the internet?
No single person invented the internet. ARPANET was created by ARPA (a U.S. Defense Department agency) and built by computer scientists at multiple universities. Vint Cerf and Bob Kahn developed TCP/IP. Tim Berners-Lee invented the World Wide Web. Many other people contributed essential pieces.
Was the internet created for military purposes?
ARPANET was funded by the military, but it was built by academic researchers and was never a classified military system. The goal was to help researchers share computing resources. The military interest was in having a communication system that could survive damage to parts of the network.
When did the internet become available to regular people?
The public internet began in 1991 when commercial restrictions were lifted. It became widely used starting in 1995 when AOL and other ISPs brought dial-up internet to millions of homes. The web browser made it accessible to non-technical people.
How fast was the first internet connection?
The first ARPANET connection in 1969 operated at 50 kilobits per second — about 6 kilobytes per second. That is roughly 1,000 times slower than a typical home broadband connection today, and about 150,000 times slower than modern fiber-optic internet.
What happened to AOL and dial-up?
AOL was the dominant ISP in the 1990s but declined as broadband (cable and DSL) became faster and cheaper. The company merged with Time Warner in 2000 and eventually became a media company. Dial-up is nearly extinct — most ISPs stopped offering it around 2010.