index.html When you navigate to a URL without a specific file in the end (domain.com or domain.com/pathrather than domain.com/path/filename.html), the browser will look for a file named index to be the first to be accessed and displayed. If it doesn’t find one, it returns a 403 error (Forbidden Error).
If the server is case sensitive, you may see the same error if you don’t use lowercase for your file and folder names. Most servers are not case sensitive, but it’s considered good practice to use lowercase for your file names, and I will be insisting on it.
Common mistakes include naming the file something other than index.html, such as or home.html (with uppercase Index.htmlI).
