The EliteBook 840 G2 has an SSD storage medium which is better than most medium processor core laptops that came out around the same time as it. Most portable PCs that have been on the market for around the same time as 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 were released around the same time as the EliteBook 840 G2.
An HDD storage medium is the worst storage medium amongst similar types of notebook PC.
Notebook PCs with a better storage medium that might also be worth looking at include the Asus UX301LA[plb_2401459_price] (SSD), the Lenovo T550[plb_2916140_price] (SSD), or the DELL Latitude 14 E7450[plb_2882106_price] (SSD).