The USB flash drive is a unique kind of PC storage toy. The keychain-size flash drive needs no batteries and has no moving parts! Instead, the USB flash drive uses the same method that digital cameras use to store images.
Your files are stored on memory cards (either removable cards or built-in memory inside the unit).
Most USB drives now range anywhere from 128MB to 64GB of storage, and after you plug one into your PC’s USB port, it looks just like any external hard drive (or a whomping huge floppy disk), but it can be unplugged and carried with you in your pocket.
These drives don’t need any extra software — Windows XP and Vista recognize them instantly — so they make a great “digital wallet.”
This figure shows a 1GB flash drive. It even has a write-protect switch so that you can safeguard your data from being accidentally erased.