[Csync2] Is csync like rsync or like unison?

[Francisco Reyes]

Trying to figure csync2 and keep reading the pdf manual.. yet some areas 
are not clear to me.

Is csync2 like rsync where I have to run it from every single host?
Or like unison where I run it from one host and it detects changes on 
the source and the target?

Say I have machines A and B
I make a change in a file in A and a change in a file in B
When I run csync2 in machine A I see the changes pushed, but a change in 
B is not getting caught when I run csync2 from machine A.