These will often contain an "index.html" page, which is usually the "root" or "home" page of your site (in other words, the first page people see when they type in your URL).
When an Internet visitor types in your registered domain name, their browser looks for the file saved as "index.html," which is the main page you've created for your website.
The hosting accounts are set up to recognize "index.html" as your starting page, unless you've installed PHP and have configured another starting page like "index.php."
The simplest web page is an HTML document saved as "index.html" and stored in your public folder on your web host.
If you've just started a new hosting plan, the odds are good that the default starting page is "index.html".
CSS in its simplest form includes a .css file and an index.html file.