There are three basic parts that make up any current day web site: the domain name, the web-hosting, and the website files themselves.
The domain name is much like an entry in a phone book. Computers communicate by using numbers, called IP addresses, to contact each other, much like you use a phone number to dial a specific person's phone. Without having a domain, you would have to tell your visitors to locate your site at: 123.456.789.123/~mysite/ instead of www.mydomain,com.
Web-hosting is much like the space that you rent out to live or have your business in. It's merely the space itself and does not include furnishings. Luckily, RocHosting provides a simple way to install many framework applications through the Softaculous icon within your cPanel. Without the hosting services, you won't have a place for your files to reside, so your domain would then become like a disconnected phone number in the phone directory, and your site files would have nowhere to stay.
In summary, you have a site visitor, who goes to your domain name, which
translates into your server IP address, then the server sends that user
your site files, which their browser represents to them as a typical web-page. You can see that without each of these 3 elements you
wouldn't really have a functioning website.