Hello everyone

I'm a bit confused with the avast 4 Server Edition. I would really appreciate if someone can help me to sort things out.
First of all I would like to know how does the server edition support network clients? And how it;s done?
Do I have to install something else beside the basic installation of server?
If I have purchased the server edition, do I have to buy avast Professional for ntw clients?
I am so confused

I hope that someone will help me.
Thanks a lot