exhaust & intake cams the same?

i was wondering if the exhaust and intake cams are the same if not how can i tell them apart. also where do i line up the marks on the cam? I know i set crankshaft on tdc on cil 1 but is their any thing other i have to worry about for setting perfict timeing on uper and lower chains

it depends on the car. some have symetrical cams and some dont.

sorry its a 92 240sx ka24de engine