Consumer-grade drives and those designed for server use come in all shapes and sizes, ranging from 3.5-inch mechanical hard disk drives (HDDs) to ultra-fast M.2 NVMe solid-state drives (SSDs).

magnetic disk or optical disc. The term is commonly used to contrast hard disks with all-electronic solid state drives (SSDs). See hard disk and SSD. THIS DEFINITION IS FOR PERSONAL USE ONLY.

A hard disk comprises one or more aluminum or glass platters, coated with a ferromagnetic material. Although the terms "hard disk" and "hard drive" are used synonymously; technically, the disk ...