VST Connections "COUNT"

I am new to cubase and I am setting up my VST connections for output. I am using an M Audio M Box 3 interface. Right now i have just one microphone connected and I will be recording only vocals in mono right now. I was wondering what is the difference between “count” when setting this up. The manual that came with cubase is telling me to set the count to 2 and configuration to mono. What if I set the count to 1? What does “Count” mean? I guess that’s my main question to summarize this all.

Thanks, makes it a little more clear.