The trends in the world are cyclical; what has been divided will eventually unite, and what has been united will eventually divide. This is also true in the storage product sector. The well-known Western Digital and SanDisk have gone through a process of competition, merger, and now separation. Western Digital and SanDisk have officially split into two independent publicly traded companies. Western Digital focuses on the mechanical hard drive sector, while SanDisk takes over Western Digital’s flash memory business, including the NAND flash and solid-state drive markets.