🌐 How the Web Works

What Happens When You Visit a Website?

Every page load involves a precise sequence of events happening in milliseconds:

1. You type a URL like https://okstem.org and press Enter.
2. Your browser asks a DNS server to translate that name into an IP address (like looking up a phone number).
3. Your browser opens a connection to the server and sends an HTTP GET request: "Please send me this page."
4. The server sends back an HTTP response containing HTML, CSS, and JavaScript files.
5. Your browser parses those files and renders (draws) the visible page.

Key Terms

• URL — Uniform Resource Locator. The address of a page: https://okstem.org/courses
• DNS — Domain Name System. Translates human-readable names into numeric IP addresses.
• HTTP / HTTPS — The protocol browsers and servers use to communicate. HTTPS is encrypted.
• HTML — The structure and content of the page.
• CSS — The visual styling of the page.
• JavaScript — The interactive behavior of the page, running in the browser.

Frontend vs. Backend

Frontend code runs in the user's browser — HTML, CSS, and JavaScript. It controls what the user sees and interacts with.

Backend code runs on the server — databases, authentication, business logic. The user never sees it directly.

This course teaches frontend development. By lesson 18 you will have a live website deployed on the internet.