The HP 13-c002dx has an SSD storage medium which is better than most portable PCs of this age and type. Most similar spec laptops that have been on the market for around the same time as 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 a similar age and type to the 13-c002dx.
An HDD storage medium is the worst storage medium amongst comparable types of laptop.