Capacitor technology is a study unto itself. Here is an excellent starting
application note that will help.
The dielectric and geometry and construction make capacitors solve different
problems with different types, eg. the best characteristics. For example in noise
work ESR a very important parameter, ceramics, multilayer ceramics, polymer
Tantalum, etc.. Another focus could be leakage, where film, Teflon, polypropylene,
and others shine at low dielectric leakage. Then you have caps for timing circuits
where C vs V of the cap, temp drift.....you can easily make a career out of just
Capacitor technology. RF work has a whole technology area itself, air spaced, piston,
silver button mica,........
http://www.kemet.com/Lists/TechnicalArticles/Attachments/6/What%20is%20a%20Capacitor.pdfThe .01, .001, to ground, are typically for noise suppression. Usually ceramic disk.
Or these days multi layer ceramic (MLC).
Regards, Dana.