The Internet Started as a Military Network, Then Became Public

The internet began in 1969 as ARPANET, a project funded by the U.S. Department of Defense. The goal was straightforward: create a communication system that could survive if part of it was damaged. Instead of one central hub that everything connected to, ARPANET used many connection points. If one broke, messages could find another route.

For the first decade, only universities and military labs could use it. In 1983, ARPANET switched to a new technical standard called TCP/IP — the same standard the internet still uses today. This switch made it possible for different networks to talk to each other. By the late 1980s, universities began connecting their own networks to ARPANET. In 1991, the World Wide Web was invented at a Swiss physics lab, and suddenly regular people had a reason to go online. The internet opened to the public, and companies began building the infrastructure to serve them.

Key Takeaways

  • The internet is made of millions of smaller networks owned by different organizations — internet service providers, universities, governments, and companies — all connected together using the same technical rules.
  • Physical cables (fiber optic, copper, and undersea) carry the actual data between continents and cities, while wireless towers handle the last connection to your home or phone.
  • Internet service providers buy access from larger networks and sell it to you; they do not own the entire internet, only the pipes that reach your neighborhood.
  • New internet capacity is built when demand grows, which is why your connection speed has changed over the years and why rural areas often lag behind cities.

Who Actually Owns and Builds the Internet

No single company or government owns the internet. Instead, thousands of organizations own pieces of it. Internet service providers (ISPs) like Comcast, Verizon, and AT&T own the cables and equipment that bring internet to your home. Larger carriers like Level 3 and Cogent own the long-distance fiber optic cables that connect cities and continents. Universities, governments, and tech companies own their own networks too.

These organizations are connected by agreements, not by a single owner. An ISP in your city buys bandwidth — the capacity to carry data — from a larger carrier. That larger carrier might buy from an even larger one. At the top are a handful of companies that own the backbone cables crossing oceans and continents. When you send an email, it travels through multiple networks owned by different organizations, and each one charges the previous one a fee for passing the data through.

The technical rules that let all these networks talk to each other are managed by nonprofit organizations. The Internet Engineering Task Force (IETF) decides how data should be formatted and sent. The Internet Corporation for Assigned Names and Numbers (ICANN) manages domain names and IP addresses. No government controls them, though they work closely with governments and companies.

How Physical Cables Connect the World

The internet is not wireless. It runs on physical cables buried underground, strung on poles, and laid on the ocean floor. Fiber optic cables are the fastest and most common for long distances. They are thin glass strands that carry data as pulses of light. A single fiber optic cable the width of a human hair can carry thousands of conversations at once.

Undersea cables connect continents. More than 400 submarine cables run along the ocean floor, carrying over 99 percent of all international data. These cables are about the thickness of a garden hose and are buried in shallow water to protect them from ship anchors. Laying a new undersea cable costs hundreds of millions of dollars and takes years to plan. Tech companies like Google, Facebook, and Amazon now invest in their own undersea cables because the demand for international data is so high.

In cities and towns, copper cables and fiber optic cables run through underground conduits or along telephone poles. The last stretch to your home — called the "last mile" — is often copper telephone wire, coaxial cable (the same type used for cable TV), or fiber optic. Wireless towers handle the connection for mobile phones and some home internet services. Each type of cable has different speed limits, which is why your internet speed depends partly on what type of cable reaches your house.

How New Internet Capacity Gets Built

The internet grows because demand grows. When more people sign up for service or use more data, ISPs and backbone carriers must add capacity. This happens in stages. First, they upgrade equipment at connection points called data centers — large buildings filled with servers and networking equipment. Then they lay new cables or upgrade existing ones to carry more data.

Building new cables is expensive and slow. Digging up streets to lay fiber takes months and costs millions per mile. This is why rural areas often have slower internet than cities — the cost per person is much higher when fewer people live in an area. Some rural areas waited decades for broadband because the financial return was too low for private companies. Government programs like the Rural Broadband Program now fund cable installation in areas where private companies will not invest.

Tech companies have also pushed for faster upgrades by building their own networks. Google Fiber, for example, is a company-owned network that runs fiber optic cable directly to homes in select cities. This forces traditional ISPs to upgrade their own networks to compete. The result is that internet speeds have roughly doubled every five to seven years for the past two decades, though the pace has slowed as we approach the physical limits of copper cables.

How Data Centers Keep the Internet Running

Data centers are the physical heart of the internet. They are large buildings — sometimes the size of a football field — filled with thousands of servers (computers that store and send data), networking equipment, and cooling systems. When you visit a website, your request goes to a data center where that website's servers live. When you use cloud storage, your files sit on servers in a data center.

Major tech companies like Amazon, Microsoft, Google, and Apple own massive data center networks spread across the world. Amazon Web Services (AWS) alone operates data centers in dozens of countries. These companies rent space and computing power to smaller businesses that cannot afford to build their own. Your email provider, your bank, and most websites you visit run on servers in these rented data centers.

Data centers use enormous amounts of electricity — often as much as a small city. Cooling the servers is one of the biggest costs. Some data centers are built near hydroelectric dams or in cold climates to reduce cooling costs. Others use innovative cooling methods like immersing servers in special liquids. The location of data centers matters for speed too — the closer a data center is to you, the faster your connection to it, because data travels at the speed of light through cables and even light takes time to cross long distances.

Why Internet Speed and Reliability Vary by Location

Your internet speed depends on what infrastructure reaches your address. In dense cities, multiple ISPs often compete, and fiber optic cables are common, so speeds can be very fast. In suburbs, one or two ISPs may serve the area, and the cables might be older copper lines, so speeds are slower. In rural areas, cables may be miles away, and wireless connections are the only option, which are slower and less reliable.

Reliability also depends on infrastructure age and redundancy. Newer cables and equipment fail less often. Redundancy means having backup routes so that if one cable breaks, data can take another path. Major backbone routes have heavy redundancy because a failure would affect millions of people. Your local connection may have less redundancy, which is why a single cut cable in your neighborhood can knock out internet for hours.

Weather affects reliability too. Heavy rain can disrupt wireless signals. Extreme cold can damage cables. Flooding can destroy underground conduits. Undersea cables are vulnerable to ship anchors and fishing nets. When a major cable fails, repair ships must be dispatched, which can take days. This is why internet companies are constantly investing in redundancy — adding backup cables and routes so that no single failure can take down service for large areas.

How the Internet Continues to Expand

The internet is still growing. Satellite internet companies like Starlink are launching thousands of satellites to provide coverage to remote areas where cables will never reach. Underwater cable projects continue to expand capacity between continents. 5G wireless networks are being built to increase mobile data speeds. Each of these projects takes years and billions of dollars.

The growth is driven by demand. Video streaming uses far more data than email or web browsing, so as more people stream video, networks must expand. Remote work and online school created sudden spikes in demand during 2020 and 2021. Self-driving cars and smart cities will require even more reliable, faster networks in the future. The internet that exists today was built to handle the demand of five years ago, and companies are constantly building for the demand of five years from now.

Frequently Asked Questions

Who pays for all these cables and data centers?

ISPs and tech companies pay for them using money from customer subscriptions and service fees. When you pay your internet bill, part of that money goes toward maintaining existing cables and building new ones. Tech companies also invest heavily because they need fast, reliable networks to run their services. Some governments fund rural broadband projects because private companies will not.

Can the internet run out of capacity?

Not completely, but specific routes can become congested during peak hours. This is why your internet might be slower in the evening when many people are online. Companies upgrade capacity before it becomes a problem, but upgrades take time and money. The backbone of the internet has plenty of capacity; the bottleneck is usually the last mile — the cable to your home.

What happens if an undersea cable breaks?

Data reroutes through other cables, so you usually do not notice. However, if multiple cables in the same area break, or if a region has only one cable, service can be disrupted for days while repair ships travel to the location and fix it. This is why companies now invest in multiple cables between major regions.

Why is rural internet so much slower than city internet?

Building cables to rural areas costs more per person because fewer people live there. An ISP might spend a million dollars to serve 100 people in a rural area but the same million dollars to serve 10,000 people in a city. Private companies focus on cities first. Government programs are now funding rural broadband, but the work is slow because the distances are long and the terrain is difficult.

Do tech companies like Google and Amazon control the internet?

They control large parts of it — the data centers, some cables, and the services that run on those servers — but they do not control the whole thing. Thousands of ISPs, carriers, and organizations own pieces. Tech companies have significant influence because they own so much infrastructure and because billions of people use their services, but no single company owns or controls the entire internet.