The Zenbook UX301LA has an SSD storage media which is better than the HDD storage media found on most medium processor cores portable PCs that are a similar 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 portable PC's storage medium (SSD) is in fact the best storage medium amongst all portable PCs of this age and spec.
An HDD storage media is the worst storage medium amongst similar types of portable PC.