how to point domain to another one ??

Hello,
I have two domains, the first one is the original one let's say domain1.com
and i want to make domain2.com point to domain1.com
so if the original page like domain1.com/video/1.htm , i can type domain2.com/video/1.htm and it will goes to the same page
how can I do that, do you have any online tutorial you could share ??
thank you

See original post by A.G