More Stupid Questions - Web Sites

Ok, need someone to clarify some technical stuff to me. I have just renewed my web hosting account and domain name, but did them both seprately and for some reason the site is not showing. I assume it is because the provider hasn't pointed the domain name to my web space because I renewed both seperately. I have sent them an email, so it should be fixed up.

Anyway, that got me thinking, when I was trying to figure out why it wasn't working. Can someone explain how web hosts "point" the domain name to the web space? And how can you transfer domain names? What does owning a domain name actually give you? I mean, is it a file or something??? I know this is probably a really stupid question, but I go by the old saying, if you don't ask, you'll never know... Can you buy another domain name and point it to a folder within your server space? For example, if I signed up for a domain name of www.dogs.com and web hosting account for 500MB, could I also buy the domain name www.cats.com and point it to that 500MB, but another folder off the root?

Ok.... Here's how it works.

As you may know every single computer on the net has an IP address. In order for the name of a website you type in to be found, it is sent to your ISPs DNS server, which then finds the relevant IP address for that name and translates the name to the IP.

The 'name' itself is stored seperately to the site. So when the name is found, it will have a list of servers for where the website can actually be found. It's therefore more than possible to have any number of domains pointing to the same hosting.

When you change your host, you also have to change where the name points to - That could be the source of your problem if you were previously unaware.