where can I found topics for every site of this network and differences between superuser and serverfault.

This is perfect network where you can find answer for almost question you need. and it's free of charge. These reasons are big plus to use it.

but there some... little...tiny... minus of this network. Some threads such as superuser and serverfault are very nearby and difference is so small, so you always think where you should post. And there no place to check this. So I have down votes only because I put my question under different thread.

but any way, why this is on StackOverflow and this is on SuperUser? 2 duplicates.