How the Internet Works
This section covers the six concepts that sit beneath every web application. Each page focuses on a single idea so that the learning is clear and incremental.
Pages in This Section
Section titled “Pages in This Section”The Internet is a global network of interconnected computers. This page explains IP addresses, packet switching, the TCP/IP protocol, and what actually happens when a URL is typed into a browser.
The World Wide Web runs on top of the Internet. This page covers URL anatomy, the HTTP/HTTPS request-response cycle, common HTTP methods and status codes, and the step-by-step journey from DNS lookup to rendered page.
Every web interaction is a conversation between a client (the requester) and a server (the responder). This page maps out the client-server model, types of servers, and the frontend/backend division with a concrete social-media example.
Domain names are human-readable aliases for IP addresses. This page walks through domain anatomy, TLDs, the DNS resolution chain, and how to register a domain.
Web applications store their data in databases. This page compares relational databases (SQL) and NoSQL, shows where a database sits in web architecture, and introduces the most widely used database systems.
The cloud means running servers and services over the Internet instead of on local hardware. This page explains IaaS, PaaS, and SaaS using a pizza analogy, surveys the major cloud providers, and points to beginner-friendly services to try first.
Link to this page (Japanese): インターネットの仕組み