Single server setup
Play this lessonThis lesson comes with an interactive animation you can break, a live-code challenge and a chapter quiz.To start simple, everything runs on one server: the web app, the database, the cache. Here is what happens when someone visits your site:
- The user types a domain like
api.mysite.com. The Domain Name System (DNS) translates it into an IP address. DNS is usually a paid third-party service. - DNS returns the IP, for example
15.125.23.214. - The browser sends HTTP requests directly to that IP.
- The server responds with HTML for web pages, or JSON for apps.
Traffic comes from two places: web apps (server-side code plus HTML/JavaScript in the browser) and mobile apps, which talk to the server over HTTP and usually exchange JSON, such as GET /users/12 → {"id": 12, "firstName": "John"}.
Analogy: a food stall where one person takes orders, cooks, and handles the money. Great for 10 customers a day. A disaster for 10,000.
Key takeaways
- DNS turns names into IP addresses.
- HTTP is the language of requests and responses; JSON is the usual data format for APIs.
- One server = one single point of failure (SPOF).