This website has some more advanced URL tricks to make your YouTube experience better. Most of these tips are for embedding videos, but there are tips for viewing as well.
In theory that's a good resource, Jimin, except that it's wrong. :) The "server name" could be anything, and has very little to do with the domain name. It is true that you can usually log in to a server (a remote computer) by giving whatever program you're logging in with the domain name, but that doesn't mean that the server itself has the same name as the website. That page is also very, very wrong in calling the the top-level domain (.org etc.) the "domain name." It's important to note that that page was almost certainly written by a librarian, not a tech professional. (Of course, I'm an English PhD, not a tech professional myself, but still.) And when I looked at the source code, I could tell that it was hand-coded in HTML, which indicates to me that it's probably many years old.
Wish there were a "dislike" button. :)