No need to apologize BTW for stating that people should try to understand first before asking. And for stating that datasheets exist for a reason 
Better?
Perfect explanation, thanx.
In short: the capacitor takes care that the voltage supplied stays more stable and (almost) unaffected by the internal working of the sensor.
For more about the working of capacitors see - http://openbookproject.net/electricCircuits/ - Part I, chapter 13