The HP Pavilion x360 has an HDD storage medium which is better than most notebook PCs of this age and spec. Most portable PCs that have been around for a similar time to it have an SSD storage medium. HDD is a traditional storage drive which stores the information on magnetic disks. HDD drives are slower than other forms of storage such as solid state drives (SSD) and flash drives.
This portable PC's storage medium (HDD) is in fact the worst storage medium across all laptops that were released around the same time as the Pavilion x360.
The best storage medium across comparable types of portable PC is SSD.