The Internet is a global network of computing devices communicating with each other in some way, whether they’re sending emails, downloading files, or sharing websites.
A world map with icons of computers on top: a laptop in Brazil, a laptop in Russia, a server in Africa, a phone in Sydney, and a phone in NY. Arrows go between the computers.
The Internet is an open network: any computing device can join as long as they follow the rules of the game. In networking, the rules are known as protocols and they define how each device must communicate with each other. The Internet is powered by many layers of protocols.
To create a global network of computing devices, we need:
- Wires & wireless: Physical connections between devices, plus protocols for converting electromagnetic signals into binary data.
- IP: A protocol that uniquely identify devices using IP addresses and provides a routing strategy to send data to a destination IP address.
- TCP/UDP: Protocols that can transport packets of data from one device to another and check for errors along the way.
- TLS: A secure protocol for sending encrypted data so that attackers can’t view private information.
- HTTP & DNS: The protocols powering the World Wide Web, what the browser uses every time you load a webpage.
You likely use the Internet every day, but you’re probably new to many of those acronyms. In this unit, we’ll learn more about each of the technologies underlying the Internet.