A 2.5-inch hard drive is a type of storage device commonly used in laptops and portable external drives. Its name refers to the physical size of the drive, which measures 2.5 inches in width. These drives are designed to store data such as documents, photos, and software, and they can be either HDDs (hard disk drives) or SSDs (solid-state drives). Due to their compact size, 2.5-inch hard drives are lightweight and energy-efficient, making them ideal for mobile devices. They connect to computers via interfaces like SATA (Serial ATA) or USB, allowing for easy data transfer and backup.