How’s really when I turn off my PC, the FLASH memory is still saving data

regarding to FLASH memory disk, what's confusing me, after we save the data on the disk so in specific place on the disk there would be bits as zeros and 1's like 101010101010101 , so this 1 and zero will still forever? I mean once I take the disk by my hand there's no electric that's connected to the flash drive/disk, so from where will 1 and 0 be for ever even though the flash drive isn't connected to the electric?

the confused question, maybe the data that I saved will be retrieve immediately once I connect my flash drive to pc/electric? and once disconnect it the electric, the flash drive will be like all zeros ....? I'm not accepting the idea how saved data as 10101001010 (zeros and 1's) would be still zeros and ones even though the flash drive isn't connected to the electric/pc, so maybe if I take it by my hand I would get a lil shock? weird.

what's confusing me, how 1 and 0 is stored as voltage 0 and 1 on the disk although my PC is off.
1 is means there's electric!! 


thanks very very very much for your cooperation.

Flash memory is an example of non-volatile memory which means it retains its state when power is turned off.  Flash represents zeros and ones as charges on floating-gate transistors.  For more detail, see Wikipedia's article on Flash memory.

Hi Ryan -- you really need to perform Google searches on some of your questions -- read up as much as you can -- and then come to us to ask about the things that still confuse you -- as opposed to just firing off questions as they pop into your head (which seems to be your typical modus operandi).Semiconductor computer/electronic memory is organized in cells. Each cell holds a single binary digit, or bit, which can represent a logic 0 or 1. Some types of memory are said to be volatile, which means they forget (lose) their contents when power is removed from the system (examples are SRAM and DRAM). When power is reapplied, these memories power-up containing random 0 and 1 values, so we don't use them until we've loaded good contents into them.Other memories are said to be non-volatile, which means they do remember their contents when power is removed from the system (one example of this is a Flash memory).At the heart of a Flash memory cell is what we might call a Flash Transistor -- take a look at the image below. On the left we have a regular MOS transistor with its source, drain, and control gate. On the right we have a Flash transistor -- observe that it has an extra "floating" gate.


Also observe that the floating gate is completely surrounded by silicon dioxide, which is an insulator, which we therefore assume will not conduct. The thing is that all of these structures are really small and the layers are very, very thin. If we apply sufficient potential, we can force electrons to jump across the silicon dioxide into the floating gate. These electrons will stay there, even when power is removed from the system. When the system is powered up, we can use the presence or absence of electrons in the floating gate to represent logic 0 or 1 states. This is how Flash memory maintains its 00110101 contents, even when power is removed from the system.
Of course there are always trade-offs. For example, SRAM is much faster to read and write than Flash memory, but it does forget it's contents when power is removed from the system -- that's why systems typically contain both types of memory.

You may try reading this Wikipedia page on Flash memory. I think you would also find my book Bebop to the Boolean Boogie explains a lot of this stuff. Maybe your local library could get a copy in for you.

So if it saves its contents although we power it off, then I might get a shock from the FLASH DISK if I take it by my hand? because if it's saving 1 and 0, 1 means there's voltage ..so I may get a shock...am I right?

Answer #1:No -- first of all -- as noted above -- the electrons are stored in the floating gates, which are electrically isolated by the insulating silicon dioxide, which means they aren't going anywhere.Secondly, we are talking about incredible small structures measured in billionths of a meter -- if you charged every cell in a Flash memory -- and then somehow took all of those electrons and applied them to your body (I can make suggestions as to where to apply them if you wish), you wouldn't even feel it.

Answer #2Yes! Absolutely! In your case I would not recommend opening any piece of electrical equipment and touching the contents with any part of your body because at some stage you are almost certainly going to receive a shock -- not from the Flash Disk, but something is going to get you.

thanks alot for your help!!!!!!!!!!!!!!may you explain what do you mean floating gates? I know transistors etc , but what do you mean with term "floating gates", and what do you mean electrically isolated? can we get electric underneth isolation material?
the electrons are stored in the floating gates, which are electrically isolated by the insulating silicon dioxide, which means they aren't going anywhere.

"floating" means not electrically connected to anything. How familiar are you with static electricity?