The Stream 13 has an SSD storage medium which is better than most notebook PCs of this spec and age. Most laptops of a similar spec and age to it have an HDD storage medium. Flash drives store data in semiconductors on a circuit board rather than using magnetic or optical media. Flash have no moving parts which makes them very fast and reliable.
An SSD storage medium is in fact the best storage medium amongst all notebook PCs of this spec and age.
Amongst similar types of laptop the worst storage medium is HDD.