A hard disk drive (HDD) is a nonvolatile computer storage device that contains magnetic disks or platters that spin at high speeds. It is a secondary storage device that stores data permanently, with random access memory (RAM) being the primary memory device. Nonvolatile means that the information is retained when the computer is turned off. A hard drive is also known as a hard drive.
Techopedia Explains the Hard Disk Drive (HDD)
A hard drive hdd mean fits inside a computer case and is held with clamps and screws to prevent it from shaking as it spins. It typically spins between 5,400 and 15,000 RPM. The drive moves quickly, allowing data to be accessed immediately. Most hard drives work on high-speed interfaces that use serial ATA (SATA) or serial connection technology. An arm with a read/write head extends across the platters as the platters spin. The arm inscribes new data to the platters and reads new data from them. Most hard drives use enhanced integrated drive electronics (EIDE), including cables and connectors to the motherboard. All data is stored magnetically, allowing information to be saved when power is lost.
Hard drives need a read-only memory (ROM) controller board to tell the read/write heads how, when, and where to move across the platters. Hard drives have disks stacked together and spinning in unison. The read/write heads are skilful by an actuator, which magnetically reads and writes to the platters. The read/write heads float on a film of air above the platters. Both sides of the platters are used to store data. Each side or surface of a disk is called a head, and each is divided into sectors and tracks. Completely tracks are the same distance from the centre of the disk. Collectively they made up a cylinder. Data is written to a disk starting from the farthest way. The read/write heads move to the next cylinder once the first cylinder is full.
A hard drive is separated into one or more panels, which can be divided into logical drives or volumes. A Master Boot Record (MBR) is usually located at the beginning of the hard drive and contains a partition information table. Each logical drive has a boot record, a file allocation table (FAT), and a root directory for the FAT file system.
Storage Capacity
Hard drive capacity is essential in determining whether someone will buy a particular device, such as a laptop or a phone. If the storage capacity is relatively small, it will fill up with files faster, whereas a drive with a lot of storage can handle far extra data.
Choosing a hard drive built on how much storage it can hold is really up to opinion and condition. If you need a drug, for example, that can store a lot of videos, you’ll want to make sure you get the 256GB instead of the 128GB, or the 64GB instead of the 8GB, etc.
The same is valid for computer hard drives. For example, do you store many HD videos or images, or are most of your files backed up online? An offline storage preference at home might lead you to buy an internal or external hard drive that supports 4TB instead of a 500GB one.