A disk with usable recording surfaces on each side is known as.
A disk with usable recording surfaces on each side is known as Double-sided disk.
double-sided disk is a disk of which both sides are used to store data.
Early floppy disks only used one surface for recording. The term single-sided disk was not common until the introduction of the double-sided disk, which offered double the capacity in the same physical size. Initially, double-sided disks had to be removed and flipped over to access data on the other side, but eventually devices were made that could read both sides without the need to eject the disk.