Hard Drives are more than just the file storage system on your computer. While it’s true that a larger hard drive will allow you to store more documents, pictures, media and to load more software, hard drives also can have a big effect on system performance and reliability. Hard drives that spin faster (expressed in RPM’s) can increase performance as can hard drive technology (for example conventional vs. solid state).
Traditional hard drives (SATA) have a highly sophisticated head, platter and motor technology. These hard drives have moving parts and the rpm (revolutions per minute) measures the speed of the hard drive. The faster the rpm, the higher the performance of the hard drive. These traditional hard drives are also sensitive to shock and vibration. This can make the drive susceptible to failure or damage.
Another type of hard drives, solid-state drives (SSDs), have no moving parts, which reduce the potential for damage or failure, providing you peace of mind that your data is protected. Also, due to the fact that they have no moving parts, they also don't have speed ratings.