Hosting and domains how they work together?

[asedt]

I just purchased my own domain and planing to fix a hosting later.

So how do things works, I have used cheaper hosting before, and had my own server. When having hosting got addresses like. http://www.SomeCheapHostingCompanyNa...MyAccountName/, and while having my own server i got an IP address to access my website.

How does it works if you have a paid/better hosting?

Lets say I have my page at http://www.SomeCheapHostingCompanyNa...MyAccountName/ and want my domain to go there.

If i have a folder http://www.SomeCheapHostingCompanyNa...Name/Somthing/ I want to get to it with http://mydomain.se/Something/ and so on for all files and folders. Then I need to do something with DNS right?

I locked into into the tool for managing my domain and I can change something called "DNS - A, Host address" that i think do what i want if i have my page at a IP adress or know the IP adress (do you always do?). And "DNS - CNAME, Canonical name for an alias" That I think can do the thing with the address, but it says in the instructions that it can't be used with my main domain, only sub domains. So I cant use it I think.

I get confused there because the only thing I want to do is to do it with the main domain. Maybe you always know the IP/address of http://www.SomeCheapHostingCompanyNa...MyAccountName/ and can use that and "DNS - A"?.

Maybe I'm on the wrong track but all other settings was crap like put it in a frame and that I newer want.

I can also change the name servers, but i don't understand what that do if anyone can explain or give some info i wold like it.

Thanks

[asedt]

Have fixed hosting now, I only changed the nameservers and all works fine.