A 3.5-inch hard drive is a type of data storage device commonly used in desktop computers and servers. It gets its name from its physical size, measuring approximately 3.5 inches in width. These drives typically offer larger storage capacities compared to smaller drives, making them suitable for storing large amounts of data, such as files, applications, and operating systems. These hard drives use magnetic disks to read and write data, providing reliable performance for everyday computing tasks. While solid-state drives (SSDs) are becoming more popular for their speed, 3.5-inch hard drives remain a cost-effective option for users needing substantial storage space.