The DELL Latitude 14 7404 has an SSD storage medium which is better than most portable PCs of a similar type and age to it. Most medium processor core laptops that have been around for a comparable time to it have an HDD storage medium. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
An SSD storage medium is actually the best storage medium across all medium processor core laptops that are a similar age to the Latitude 14 7404.
An HDD storage medium is the worst storage medium amongst comparable types of laptop.