The Lenovo S21e has a better storage medium than most notebook PCs that have been on the market for more than a year. This notebook PC has an SSD storage medium, whereas most laptops of a similar age and spec 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 across all medium processor core laptops that came out more than a year ago.
An HDD storage medium is the worst storage medium across comparable types of notebook PC.