Venus GPS 1PPS configuration

I have a Venus634LPx GPS on a breakout board from SparkFun. Read more about it in my previous question.

The configuration program gives me the option to configure "1PPS Timing":

Here I can choose between "Survey", "Static" and "PVT" (Position, Velocity and Time). The Venus838LPx datasheet talks about these modes, but not the Venus634LPx datasheet.

• What do these modes mean? I find the datasheet confusing.
• Is it something unique to the 838, or does the 634 also have these modes?

So the options in my question is not applicable to the Venus634LPx chipset. The device they suggested uses the Venus822A chipset.