Web & APIs

browser

/ BROW-zur /

A browser is the program you use to visit websites — Chrome, Safari, Firefox, Edge. Its job is to fetch a web page from some server far away and then draw it on your screen as something you can read and click. Everything you do 'on the web' actually happens through a browser.

Under the hood it's running three things a website sends it. HTML is the page's structure and words; CSS is the styling — colours, fonts, layout; and JavaScript is the behaviour that makes the page react when you type or click. The browser takes those three, assembles them into the page you see, and keeps it lively. In that sense a modern browser is less a viewer and more a little machine that runs other people's programs.

It also handles the messy plumbing for you: looking up addresses, opening a secure connection, downloading images, keeping you logged in. You type 'go here', and the browser quietly does the fetching, decoding, and drawing — so the whole web feels like one smooth place rather than thousands of separate servers.

You type:   example.com
Browser →   fetch the page over HTTPS
        →   read its HTML, CSS, JavaScript
        →   draw it on screen, and keep it interactive

The browser fetches a page, then runs its HTML, CSS, and JavaScript to show it.

Every browser ships a JavaScript engine — which is why a web page can run real code, not just show text.

Also called

web browserChromeSafariFirefox