In the S models, the data storage is on a memory chip inside the tablet that is similar to a SDcard. In that it has no moving parts, it is called "solid state". I called it a flash drive because the flash drives (or thumb drives, or USB drives) that you plug into the USB port of your computer are made the same way. I named it that way in particular way to tie it into the S on the end of the model number. The S units are the ones that are 8Gb or 16Gb.