What is flash memory on a digital camera?

Im planning on buying a camera soon, and i don't know what flash memory is, but I feel it's important.What is flash memory on a digital camera?
All digital cameras now use FLASH memory.





It is memory that can be rewritten by applying power, but which retains information when power is removed.What is flash memory on a digital camera?
Flash memory is a type of static memory storage (retains the information even without a constant source of power, unlike RAM in a computer) that is rewritable and erasable. It gets its name from the fact that you can ';flash'; an entire block of memory to erase it, unlike pretty much any other medium where you have to overwrite the data to truly erase it (when you ';delete'; a file, the device will usually just remove any references to it from the File Allocation Table, which will prevent it from being able to find it again later).





Many cameras will come with a tiny amount of onboard flash memory that can't be removed, but all digital cameras will have the ability to write to some form of removable media (there are still video cameras that use DVDs, but pretty much all still-photo cameras have switched over to one form of flash memory or another).





The current most common formats are the older CompactFlash for large DSLR cameras, or Secure Digital for compact and ultra-compact models. xD and MemoryStick are both proprietary formats that have not caught on well with many other manufacturers besides the ones that own those respective formats. CompactFlash is bulky, which keeps it at the front of the pack in terms of maximum capacity, and allows it enough room that you can even buy tiny hard-drives that are built to the CompactFlash specs. SD is much smaller, and has at least the same capacity by physical volume, if not more. Both formats have enough acceptance that most modern computers will include built-in card readers for one or both types, and that has led to other manufacturers designing accessories that use those ports as interfaces, such as dial-up modems, WiFi adapters, Bluetooth adapters, barcode readers, GPS locaters, and even an SD reader that will fit into a CF slot (for use in either a camera or a computer) and SD readers that will accept either mini-SD or micro-SD cards that work in PDAs or cel phones.





Presently, the SD format is beginning to overtake the CF format for general use, so I'd suggest using that as a primary criteria for your purchase so you know you'll be able to buy memory cards through the entire life of the camera (and even keep them to use when it comes time to replace this camera). As for which cards to buy, my advice would be the SanDisk USB Plus cards, which will write fast enough to record video on most cameras, but can also be folded in half to reveal a USB plug so you can dump your photos to any computer with a free USB 2.0 port several times faster than the fastest SD card could in a dedicated SD reader.
Flash memory is a non-volitile memory. It doesn't require constant battery power to keep the information.





They use to make flash kits that allowed you to make pre-programming things, like arcade games on chips. To get rid of the game you had to put the chip into something that ';flashed it'; or made it erase things.





Like a VIRTUAL magnet.





Your computer Bios uses flash memory. When you upgrade it the new program replaces the old by ';flashing'; the chip.





This is how memory cards work. SD, XD, CF, SM.





Computer memory requires power be on to retain information. It is VOLITILE.





Thus in your camera if you save pictures in internal memory and remove the batteries from the camera, those pictures will still be there in two years (unless you accidentally run the camera through some type of electrical field that might ';flash it';) when you put the batteries back into the camera.
Flash memory are little cards you can pop into the camera and then view on your computer. They differ in price depending on how many pictures they can hold. You should get a few, though you can always just buy one high-capacity one and erase it when you've downloaded the pictures onto your PC. That's what I do with my Olympus.
Simple Answer: Their memory cards that the camera stores the pictures on.