Hard Disk Drive (HDD)

A hard disk drive (HDD), also known as a hard disk or hard drive, is a device used for storing and retrieving data in modern computers. HDDs typically offer several gigabytes or even terabytes of storage capacity. The drive consists of one or more rotating disks, called platters, which are coated with magnetic material. The platters store data in concentric circles known as tracks, with the data recorded electromagnetically. Each platter is paired with magnetic heads mounted on a moving arm. These heads are responsible for reading and writing data to the platters as they spin. Data on an HDD is accessed in a random-access manner, meaning any piece of data can be retrieved directly without needing to follow a sequence. When the drive reads or writes data, the heads move to the correct position on the disk, a process called a seek. The access time for retrieving data typically takes a few milliseconds. Data on the platters is divided into sections called sectors, each with a unique Logical Block Address (LBA), which helps define where the data is stored on the disk. Data is stored as magnetic polarities on the platter, where one side represents 0 and the other side represents 1. By reading this binary code, the computer can interpret and understand the data stored on the hard drive.