How Does the Internet Work?

Aurora, IL

This graphic illustrates the connectivity the Internet facilitates every day.

The Internet is a crucial part of our everyday lives today, as it forms the basis for a large portion of our social interactions. It allows people from all over the world to connect with one another and access whatever information they'd want instantly. Though the Internet may seem like a vast and complex piece of technology, it is only based on a few key principles along with simple software and hardware. By learning the ins and outs of the Internet, you can protect yourself and even teach others.

The Internet is a system of interconnected networks, hence the name. A network is a group of computing devices that can communicate with each other. These computing devices send messages to each other and work together to accomplish a common task. These networks can then communicate with each other, creating a worldwide connection between all devices. The main hardware that facilitates the Internet is the router, a device that intercepts radio waves and distributes them to a specific computer. On the Internet, data is sent through the air as radio waves or through underground cables and wires. These wires are called fiber-optic cables and are used for speedy transfer of large data that may not be possible over the air. These cables transmit light in a certain fashion so the router can decipher its meaning and transmit the right information.

One of the most important features of the Internet is the packet. A packet is a portion of a message that is sent through routers to the right destination. When a computer sends a message over the Internet, the message is broken up into multiple packets. Along with data, the packet contains metadata about routing information that will help it reach the destination. Packets are at max 64 kilobytes, but they are often smaller to maximize efficiency. Once packets reach their destination, the router’s protocols (either TCP or UDP) will reassemble the packets and transmit the right information. TCP, or Transmission Control Protocol, will organize the packets in the right order. If it finds that a packet is missing, it requests that packet to be sent again. UDP (User Datagram Protocol), on the other hand, is much faster than TCP but does not request missing packets. TCP is most often used for situations in which reliability matters over time, like emails, while UDP is used when time is very important, like when a user is gaming or playing videos.

This chart shows the protocols you will encounter from bottom to top.

The other main feature of the Internet is the protocol. There are numerous protocols in use on the Internet. Because computers may run on different hardware and software than one another, protocols were created to make a worldwide standard for computers to access the Internet. The most important protocol is the Internet Protocol (IP). IP is what helps packets travel across the Internet and arrive at the right router. An IP address is a certain string of letters and numbers attached to a device or domain that helps identify it on the Internet. When a device (for example, a laptop) sends a request to go to a website (like Twitter, YouTube, or Google, for example), that request is broken up into packets. The packets contain the IP address of the laptop and the IP address of the website’s domain. TCP and UDP, previously mentioned protocols, are the transport protocols for IP. HTTPS (and its predecessor HTTP) is the main protocol for sending information and establishing a connection between a device and a website. You can recognize this at the beginning of almost every URL you use throughout the day. HTTPS is important because it encrypts data over the Internet in order to deter hackers and other bad actors. HTTPS utilizes public key encryption, a complex encryption technique that makes use of a public key and a private key to safeguard any information transported through the Internet. Websites that use HTTP, as opposed to HTTPS, are often marked "not secure" by browsers, so users must exercise caution when using such websites.

Overall, the Internet is a vast and complex piece of technology that has been created and improved upon by millions of people and organizations. By understanding the ways in which the Internet works, you can be more aware of your virtual surroundings and stay cyber safe. Like everything, the Internet has its benefits and drawbacks, so knowing its ins and outs can help you minimize those drawbacks.