The DELL XPS 13 9343 has an SSD storage medium which is better than the HDD storage medium found on most portable PCs of a similar spec and age to it. 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 in fact the best storage medium amongst all portable PCs of a similar spec and age to the XPS 13 9343.
An HDD storage medium is the worst storage medium across similar types of notebook PC.