Alternatively, byte capacity estimates for a next-gen 120mm optical disc would have been welcome. For now, the boast of “ultra-high-density optical memory” is all we get.

USB drives and optical discs are also storage. Memory is made up of "random access memory" (RAM) chips, which are upgradable by the user in a desktop computer but not in a phone or tablet.

The most common types are CD, DVD and Blu-ray. As removable media, optical discs superseded the earlier magnetic disk cartridges because they weigh less, have higher capacities and are not subject ...