A solid-state drive is considerably quicker than any regular hard disk. It is because an HDD uses spinning disks, that can rotate only so fast and the more information is read and written, the sluggish and hotter they get, whereas an SDD operates with modules of flash memory, so there are no actually moving components. The access speeds for an SSD are drastically higher, which makes this kind of drives the right solution in case speed is needed. That's why SSDs are in many cases employed for the Operating System on a personal computer and for storing data that's used repeatedly on servers. Numerous providers also use a combination of both drives, so they save the data on hard drives, but they use several solid-state drives to cache the more frequently used data and as a result, the data loads a lot faster while the load on the HDDs is reduced because their disks have to spin less frequently to read and write.