what is SSD ?

A solid state drive or SSD can speed up the performance of a computer significantly, often more than what a faster processor (CPU) can. A hard disk drive or HDD is cheaper and offers more storage (500 GB to 1 TB are common) while SSD disks are more expensive and generally available in 64 GB to 256 GB configurations.

Like a memory stick, there are no moving parts to an SSD. Rather, information is stored in microchips. Conversely, a hard disk drive uses a mechanical arm with a read/write head to move around and read information from the right location on a storage platter. This difference is what makes SSD so much faster.