The Toshiba Z930 has an SSD storage media which is better than most portable PCs of a comparable age and spec to it. Most medium processor cores notebook PCs that have been around for a similar time to it have an HDD storage media. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
This notebook PC's storage medium (SSD) is actually the best storage medium across all laptops of a similar age and spec to the Z930.
An HDD storage media is the worst storage medium across comparable types of notebook PC.