Beginner Fundamentals
How the Internet Works
Understanding the backbone of the web: packets, protocols, and routing.
What is the Internet?
The Internet is a global network of interconnected computers that communicate through standardized protocols. It's the infrastructure that enables the World Wide Web, email, file sharing, and countless other services we use daily.
How Data Travels
When you request a webpage, your data doesn't travel in one piece. Instead, it's broken down into small packets—typically around 1,500 bytes each. These packets travel independently across the network and are reassembled at their destination.
Key Components
- Packets: Small chunks of data containing a portion of your message plus routing information (source and destination IP addresses).
- Routers: Specialized devices that read packet headers and forward them toward their destination, choosing the best path based on network conditions.
- IP Addresses: Unique numerical identifiers for every device on the network. IPv4 uses 32-bit addresses (e.g., 192.168.1.1), while IPv6 uses 128-bit addresses for the growing internet.
- ISPs (Internet Service Providers): Companies that provide access to the internet backbone and route traffic between networks.
The TCP/IP Model
The Internet operates on a layered model:
- Application Layer: Where your apps live (HTTP, FTP, SMTP)
- Transport Layer: Manages end-to-end communication (TCP, UDP)
- Internet Layer: Handles addressing and routing (IP)
- Network Access Layer: Physical transmission of data (Ethernet, WiFi)