The Stream 11 has a better storage medium than most portable PCs of a similar spec and age to it. This laptop has an SSD storage media, whereas most comparable spec portable PCs that have been available for a similar time to it have an HDD storage media. 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.
This portable PC's storage medium (SSD) is actually the best storage medium across all medium processor cores notebook PCs that are a comparable age to the Stream 11.
Across similar types of portable PC the worst storage medium is HDD.