A solid-state drive (SSD) is a media that uses flash modules to store data. The SSDs remain fairly new and more pricey when compared to standard hard disk drives (HDD), but they're faster, so they are frequently used for Operating Systems and apps on both home PCs and hosting servers. An SSD is preferred because it doesn't have spinning disks that limit its speed and may cause overheating like it could happen with an HDD. Most companies use SSDs for caching purposes, so all site content that is accessed more often will be held on such drives, while all the other content will be kept on conventional HDDs. The reason to use this kind of a setup is to balance the price and performance of their web hosting platform and to decrease the load on the HDDs caused by countless reading and writing processes.