please read some basic books..... i suggest razavi for a good understanding.... do u think teaching a device here online using these posts is easy,.,..
The genuine way to know MOSFET is to go through some books,some online articles..and if u find some online video lecture....it will be the best choice.
How much do you know about electronics? Specifically capacitance, and in depth PN junction theory (diodes,NPN, PNP transistors). If you know these things, than I can explain it in one paragraph. If not I suggest that you take some courses at a school.