Someone said that 'this is very easy'
Someone like me said, I can't remember this ... so ... I have to post it
$ scp file_name user@server:/path/to/directory
And, you can transfer file from between another server like this command:
$ scp user_a@server_a:/path/to/file_name user_b@server_b:/path/to/directory
For more information ... use google :P