The HP ProBook 650 has an SSD storage medium which is better than most laptops that have been on the market for around the same time as it. Most portable PCs that have been on the market for a similar 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.
This notebook PC's storage medium (SSD) is in fact the best storage medium amongst all medium processor core laptops that are a comparable age to the ProBook 650.
An HDD storage medium is the worst storage medium amongst comparable types of notebook PC.
If the storage medium of this HP laptop is not good enough for you then you might also want to consider the DELL Latitude 12 E7250 (SSD).