The PM1663a by Samsung and the Ultrastar He10 by Western Digital are tremendously large hard drives. Whereas the Ultrastar He10 can hold 10 terabytes of data, the PM1663a is able to store as much as 16 terabytes of information.
While the hard disk by Western Digital is a traditional hard disk drive that uses data platters to store data, the PM1663 is a solid state drive that stores data on flash memory components. To reach 10 terabytes on a traditional hard disk, Western Digital uses a technology called HelioSeal. The technology seals helium inside the drive and prevents air from entering or getting out of the hard disk. As helium has a lower resistance than normal air, the hard disk can hold more disk platters and, consequently, more storage space.