A solid-state drive is substantially faster than any regular hard disk. It is because an HDD uses rotating disks, that can rotate only so fast and the more data is read and written, the slower and warmer they get, whereas an SDD uses modules of flash memory, therefore there aren't any physically moving components. The access speeds for an SSD are drastically higher, which makes this kind of drives the right solution every time speed is needed. Because of this SSDs are in many cases used for the Operating System on a PC and for storing data which is used frequently on hosting servers. A large number of service providers also use a combination of the two drives, so they store the data on hard disk drives, but they use one or more solid-state drives to cache the more often used data and due to this fact, the data loads faster while the load on the HDDs is lowered as their disks need to spin less frequently in order to read and write.