Infrastructure includes physical structure, equipment, and services for society to function well
What structures, equipment, and services are needed for a society to function well?
Examples of infrastructure include roads and bridges, water lines and sewer lines, telephone lines and radio towers, power lines and power plants. We can classify infrastructure under categories such as transportation, water, communications, and energy.
Transportation infrastructure includes roads, bridges, rail lines, and freeway overpasses
Transportation infrastructure helps connect cities and communities, so that people and things can get to where they need to go. Roads are shared infrastructure that transport people by car, bus, taxi, or bicycle. Roadways include freeways, bridges, and sidewalks, too. Rail lines, trains, and train stations also help move people and things. Often a region or country may have public rail transportation. Public transportation can move people efficiently while reducing pollution from cars on the road. Airlines, airports, and control towers are part of transportation infrastructure as well. Some parts of transportation infrastructure are provided by local, regional and national governments. Examples of public transit infrastructure include local roads, freeways, regional public railways, and air traffic control. Some parts are provided by private companies. Examples of private transit infrastructure include airlines (such as American Airlines), private train systems (such as Union Pacific), and private bus companies, like Greyhound.
Water infrastructure includes clean water distribution and waste water removal
We use water to drink, shower, cook, water lawns and farms, and more. It is important to get clean, safe water for drinking and cleaning. We get our clean water through water infrastructure. Water infrastructure includes treatment plants, water sources such as reservoirs, and miles upon miles of pipes to carry water to homes, businesses, and farms.
The water we drink comes from reservoirs, wells, rivers, and lakes. It needs to be cleaned before it arrives at your house. Water treatment plants clean the water so that it is safe to use. The water plants remove solid matter, kill bacteria, algae and other contaminants, and filter the water so that is clean and clear.
We also need to remove dirty water - sewage - from our homes and businesses. Sewer lines collect waste water from toilets, shower drains, and sink drains and take the waste water to sewage treatment plants. Sewage treatment plants clean the water so it can be safely disposed.
Energy infrastructure includes power generation, transmission, and distribution
Energy is an important part of our infrastructure. Energy infrastructure provides energy to power our homes, businesses, and schools. We call our energy infrastructure the "electric grid" or the "energy grid".
Key parts of energy infrastruture are power generation, transmission, and distribution. Power generation is how we get useful energy out of energy sources like coal, the sun, wind, and nuclear power. Transmission lines move electricity around the country to where it is needed. And distribution is the final step to bring electricity to homes and businesses.
Before we had energy infrastructure, people had to use candles and torches for light, and fires for heat. Now we can light, heat, and cool our homes, and power our televisions, computers, refrigerators, other household equipment. People want their energy to be available whenever they want to use it. You can read more about the grid and energy sources on the Energy part of this site.
Communications infrastructure includes telephone systems, cellular, radio, internet, and television
You probably use communications infrastructure fairly often. Whenever you pick up the phone and call someone, you are using communications infrastructure. When you text someone, or watch TV, you are as well. We call it "communications infrastructure" because it is infrastructure used to communicate. That communication can be one-way, like listening to a radio program or watching a movie. Or, the communication can be two-way, such as a conversation on the phone or through text messages.
Telephone lines are a key part of the communications infrastructure. The telephone system uses telephone lines that have been strung all over the country. That set of wires and all the equipment that supports it is the reason that you can pick up a phone and call someone.
Even if you only use a cell phone, you are still using communications infrastructure for your calls. The cellular system is another key part of communications infrastructure. Cell phones use wireless signals that are sent to and received from cellular towers. You can only make a call from a cell phone if you have a cell tower in range. Cellular infrastructure has been built up over the last 40 years.
When you watch a television show, you are also using communications infrastructure. Some shows are available on "broadcast" television channels. That means that those shows are available for free to anyone that has a TV and an antenna that can receive the TV signal sent over the air. Some shows are only on "cable" channels, like HBO, CNN, or Showtime. To watch those shows, you need to pay for access to them. They are called "cable" channels, even if you are using a satellite dish to receive the signals from a satellite out in space. These days you can also watch TV shows on a computer, or table, or phone - but in any case, you are relying on communications infrastructure. In that case, you are using the part of communications infrastructure that provides internet access.
If you are listening to the radio, you are also using communications infrastructure. Radio signals are sent from tall towers over the air. You can receive them, for free, if you have a radio or any other device that can tune to the electromagnetic frequencies used for radio stations. There are also "radio" stations that you can access using the internet, for example through a computer in your house, as well as "radio" stations you can access through satellite signals. These are not radio stations in the typical way that we think of radio - they cannot be accessed by tuning to an AM or FM station. But they are sometimes called radio. No matter how you get your "radio", you are using communications infrastructure.
Finally, the internet is part of communications infrastructure, too. The internet consists of interconnected networks that allow communications to pass through them in standard ways. Parts of the internet are connected in various ways: through wires, wirelessly, through fiber optic lines, satellite transmissions, and more. The internet infrastructure allows us to send emails, visit web pages, listen to music on the web, watch movies from your computer, and many more things. You can read more about computer networks on the Computing section of the site.