Flash Memory's Inner Workings

Not to sure if this is the right place but,
I recently got one of the flash memory based thumb drives, it looks like this:

The casing it is in is clear and it got me thinking about how these things work, ive been curious to know how all of the types of nonvolatile memory work, i.e. compact flash etc. Im sure there is no battery so it dosent need to be powered all of the time but how do they store the data without losing it when the power goes away.
Thanks in advance,
xb-70

http://computer.howstuffworks.com//flash-memory.htm


Perhaps that will help.

I see, now i understand, thank you very much!