The Zotac ZBOX-CI321NANO-U-W2A has an SSD storage medium which is faster than most similar spec computers that came out more than a year ago. Most comparable spec computers that have been available for a similar time to it have an HDD storage medium. Solid State Drives (SSD) store information in transistors on a circuit board rather than on optical or magnetic media. This has the advantage of being much faster than a traditional HDD drive.
This PC's storage speed (SSD) is in fact the best storage speed across all few processor core computers that have been available for more than a year.
An HDD storage medium is the worst storage speed across similar types of PC.