Hi, Metin.
>I see you're a Microsoft employee. Best wishes with your new job.
I'm actually a full-time contractor, so I keep my independence. Thanks for the good wishes.
>Sorry, but you wrong. He should buy licences for server which is his online user count at same time. These licences are installing to server, not clients. Different clients can access but client count cannot exceed server's terminal user licences count.
The licenses are installed (and counted) on the server, but they are Client Access Licenses (CALs), and you can purchase them by device (one per PC) or by user (one per concurrent user). It has to do with the kind of access you will provide. In Alex case, he can purchase them by device and pass the cost up to his customers.
Regards,