what's the overwatch?

[chocorito]

is it like an ai that looks over every combine troop or a ai integrated into the combines suit? or something like that

[calembredaine]

combine overwatch's officially the name of the human police/military working for the combine.
but yes, what the soldiers refer to as "overwatch" is basically an ai monitoring forces on earth. it's the same system giving commands from the citadel with a feminine voice.