A solid-state drive (SSD) is a media that uses flash modules so as to store data. The solid-state drives remain relatively new and more expensive than the classic hard disk drives (HDD), yet they are considerably faster, so they are frequently used for Operating Systems and apps on both home computer systems and web servers. An SSD is recommended as it doesn't have spinning disks which restrict its speed and may even cause overheating as it could happen with an HDD. A lot of companies use SSDs for caching purposes, so any content which is accessed more frequently will be stored on such drives, while all the other content will be held on regular HDDs. The reason to use this type of a setup is to balance the cost and performance of their hosting platform and to decrease the load on the HDDs caused by countless reading and writing processes.