Traditionally, your site only needed an `ico` favicon file. Although it looked like a single file, it had multiple file sizes embedded. Today, however, the ico is only needed for legacy browsers, and it is safe just to include a single 32 pixel file. And that’s only if you want to support quite old legacy browsers. Modern browsers support the SVG format. These files are typically very small as they use vector graphics under the hood. That also means they look good at any size. Finally, for phones, you can include a few extras. These will be used as your site’s app icon when the user saves your site to their home screen.