Webpage source information

No. HTML pages are like pieces of paper in a file cabinet. They may or may not belong to the person who owns the ".com" domain name but the person that holds the domain names determies who can put their HTML pages up on their site.

There is no requirement to register HTML pages so there is no registry of them to search.

Fishin' has it.

Think of it like this:

.com (or net or org etc) is what's called a "top level domain".

That combined with the name (e.g. able2know) is the address, the URL. That must be registered.

www. is a subdomain that just points to the http serving section of the site.

There are some other common subdomains like ftp etc.

.html or .php etc are just file extentions.