ah, yeah, your not using Maya or anything, so it would probably be known as something different, if its on there at all, but basically occlusion gives everything a really nice white txture that makes things look sexy, gives realistic shadows and stuff.
eg
[link][link]Please excuse these images, they are not my own, they are found via google image search.
ive just downloaded this SketchUp thing, i use Maya on my animation course. really nice render and modelling. looks really good, keep it up!