The browser as a runtime

Welcome to the Frontend Masterclass. I'm Param. We are going to build a real frontend from the ground up, starting with raw HTML, CSS, and JavaScript and ending with a Next.js app that talks to a real backend. The goal is for every layer of the modern stack to finally click into place.

The browser runs three languages. HTML describes the structure. CSS describes the appearance. JavaScript describes the behavior. Frameworks stack on top of these, but the browser itself only speaks these three. Understanding them well is how you stop fighting the framework.

Because React is an abstraction over DOM manipulation and Next.js is an abstraction over React. Every abstraction leaks eventually. When you understand the thing underneath, debugging the layer on top stops being guesswork.

What the browser actually runs

HTML becomes a DOM tree. CSS styles it. JavaScript reads and mutates the tree at runtime. Frameworks live on top of all three.

Quiz: Quiz

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