Solid State Drives are hard disks made from arrays of solid-state electronic storage chips.SSDs are composed of control units and storage units (FLASH chips, DRAM chips). Solid state drives in the interface specifications and definitions, functions and methods of use and ordinary hard disk's exactly the same, in the product shape and size is basically the same as the ordinary hard disk (emerging U.2, M.2 and other forms of SSD size and shape and SATA mechanical hard disk is completely different).
Fast - Because SSDs do not have the mechanical structure of a regular hard drive, the system is able to complete I/O (input/output) operations on any of the storage units in less than 1ms. Also, SSDs do not have the seek problems of mechanical hard disks.
Extended Information:
The more common SSDs on the market are LSISandForce, Indilinx, JMicron, Marvell, Phison, Goldendisk, Samsung, and Intel, and many other types of master chips. The master chip is the brain of the SSD, its role is to rationalize the allocation of data load on each flash chip, and the second is to undertake the entire data transit, connecting the flash chip and the external SATA interface. The difference in capability between different master controllers is huge, in terms of data processing capabilities, algorithms, and read/write control of the flash chips, which can directly lead to performance gaps of up to several times in SSD products.