2 domains reference same files

[squid44th]

How do I get 2 domains to reference the same files. I have 1 domain, the main one with files... domain1.org. I also want domain2.org to reference domain1.org files, but be presented in the address bar as domain2.org files. How do I accomplish this?

In my old server it was called a domain pointer, where it points domain2.org to domain1.org but says domain2.org if you get the picture.

Thanks in advance.

[verdon]

I think what you want is a 'parked' domain.