Naturally, the electronic photography system needs another device to store the
image signals. Two primary methods have been adopted to perform this storage
function: analog and digital. Analog electronic still cameras, which were once on
the market, use a kind of floppy disk that electromagnetically records the image
signals in the form of video signals. In digital still cameras, the image signals from
the image sensor are converted to digital signals and stored in digital storage devices
such as hard disks, optical disks, or semiconductor memories.