This document compares solid state drives (SSDs) and hybrid hard drives. It provides background on SSDs, noting they have no moving parts and use flash memory instead of magnetic disks. SSDs offer faster speeds but have limited storage capacity and lifetime write limits. Hybrid drives combine a small SSD cache with a standard hard disk, offering faster access to frequently used files while providing higher storage capacity at a lower cost than SSDs alone. However, hybrid drives are slower than SSDs for cached files and have shorter lifetimes if the SSD cache is managed poorly. The document concludes SSDs are best when speed is the top priority, while hybrids are suitable when both speed and capacity are important.