The Lenovo S21e has a better storage medium than most similar spec laptops that were released around the same time as it. This portable PC has an SSD storage medium, whereas most medium processor core notebook PCs that have been around for a comparable time 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 actually the best storage medium across all similar spec portable PCs that are a comparable age to the S21e.
An HDD storage medium is the worst storage medium across similar types of portable PC.