on my dedicaced server, i host multiple website.
Simple question : what do i need to enter in
website1.com instead of
What do i need to put in there ?
You're specifying the name of the server, literally. Pick the one that you want your server to be, it's up to you.
It will be the default name for any services you run on the server unless you specify otherwise. For example, this is often going to be the default host to remotely connect to the server to such as with SSH. Nevertheless, many other protocols will be specified to utilize hostnames outside of your server's hostname. For example, rarely will Apache's primary role be to serve files on the server's default hostname.
You can call your server as you want, this doesn't need to have any relationship to the services or web sites it's hosting. This is particularly true if it's hosting multiple web sites.
E.g. if your server has the ip address
Note that the first name (after the address) should be the full qualified domain name (fqdn), any other names, including your hostname without a domain, should follow. This is because
and this on the first line in
(On most systems, you don't have control over this; it is filled with information from the DHCP server. But that's ok, this domain is only used for when you look up a host without specifying a domain; it doesn't mean this domain is valid for your host.)