The Fujitsu LifeBook S904 has an SSD storage media which is better than most comparable spec portable PCs that have been on the market for a similar time to it. Most medium processor cores notebook PCs that have been on the market for around the same time as it have an HDD storage media. 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 media is in fact the best storage medium amongst all medium processor cores notebook PCs that have been around for more than two years.
Amongst similar types of notebook PC the worst storage medium is HDD.