The Toughbook 53 has an SSD storage medium which is better than most medium processor core notebook PCs that were launched around the same time as it. Most laptops of a similar type and age 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 amongst all medium processor core notebook PCs that came out around the same time as the Toughbook 53.
An HDD storage medium is the worst storage medium across comparable types of portable PC.