This "localhost" is the default dummy name for the local loopback interface with the
If you really don't like this name then try to modify it in "/etc/hosts" to "any_new_free_name".
Then reboot your machine and check if the modification works by running "ping any_new_free_name"
> ping any_new_free_name
should respond with something like
PING any_new_free_name (127.0.0.1) from 127.0.0.1 : 56(84) bytes of data.
64 bytes from any_new_free_name (127.0.0.1): icmp_seq=1 ttl=255 time=0.053 ms
But i think it's not a very good idea to change it!
BTW Your hostname is that name you get if you run the command "hostname".