While both hard disk drives and solid-state drives are designed to store data and keep it readily accessible to the user, they use fundamentally different methods of doing so.
Hard disk drives (HDDs) are electromechanical devices that use moving parts such as motor-driven magnetic disks and movable read/write heads to store data.
Solid-state drives (SSDs) contain no moving parts and instead use Flash or RAM based memory chips to store data.
Standard hard disk drive optimization methods, such as defragmentation and program re-alignment, work by physically reorganizing data on the drive to create optimally located, contiguous regions of stored information and free space. This reduces the amount of movements the drive heads must make when reading and writing data, resulting in improved overall performance.
SSDs do not contain moving parts and therefore optimization methods that rely on physical reorganization of data have no effect on their performance other than to cause unnecessary wear and tear on the drive.
When you delete a file from a drive (HDD or SSD), the data is not immediately removed. It is instead marked as "deleted" and will from then on be seen by the system as free space eventually to be overwritten by new data.
Though solid-state drives provide many benefits over standard hard disk drives, unlike HDDs they are unable to overwrite old, deleted data as a single step. Instead SSDs must first reset the parts of their storage that contain this deleted information before new data can take its place. This two-step write process negatively impacts performance, especially when working with large files, or many files at once.
SSD Accelerator eliminates the performance draining aspect of this additional "reset" step by resetting deleted data when the drive is not in use. This ensures that you will get optimal performance out of your solid-state drive when you do need to use it.