Boy, if you didn't know this stuff, I don't know how you'd know this stuff.
This is called interoperability and explained in the documention, see
To get a better understanding of the history and the relation between Open C and NXOpen UF Wrapper, see also
At one point you could take a training course in API from Siemens (I think actually run by DAA, at least at one point).
Not sure if it is still in the catalog.
Production: NX10.0.3.5 MP16/TC11.2
I'd rather be e-steamed than e-diseaseled
While courses are nice, I think PLM fixing the underlying problem - bad documentation - would be much better.
While there is an API reference, most functions (mainly looking at Python here, but I think the same is true for all languages) have zero explanation. Especially discovering functionality is extremely hard this way.
e.g. If you don't know handles exist, there are zero cross references from other functions. Like a "see also" in the documentation for Object.Tag.
A while back I proposed having a public wiki for the API reference, so that users can help themselves, but there wasn't much resonnance.
Maybe we all should make a weeky ritual of escalating this to management until they get some priority to do this. I mean, this is not cheap software we're talking about here, and it wouldn't even be that much work. One can dream...