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HTML is the structure: it defines the content and its parts (headings, paragraphs, images, links). CSS is the style: colors, fonts, spacing, and layout. JavaScript is the behavior: it makes things respond, like menus opening, forms validating, and content updating without a full page reload. Every website uses all three.
A useful analogy is a building. HTML is the frame and rooms, CSS is the paint and furniture, and JavaScript is the electricity and plumbing that make things actually work. Remove any one and the site is broken, plain, or lifeless.
These three run in every browser with no plugins, which is why they're the foundation of the web. Frameworks and tools sit on top of them, but underneath, it's always HTML, CSS, and JavaScript reaching the browser.
Updated July 2026
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A framework is a pre-built foundation of code that handles common tasks so developers don't rebuild them every time: routing, data handling, updating the interface, and structure. Popular frontend frameworks include React, Vue, Svelte, and Angular. Frameworks like Next.js build on React to add server rendering and more.
Web accessibility means building sites people with disabilities can use, including those who rely on screen readers, keyboard navigation, or captions. The standard is WCAG, and as of 2026 the current stable version is WCAG 2.2, with Level AA as the practical target that most laws reference.
When you type an address, your browser asks a server for that page, the server sends back files (HTML for structure, CSS for style, JavaScript for behavior), and the browser assembles them into what you see. The whole exchange usually takes under a second and repeats every time you click.