What is hard disk and types of hard disk
A hard disk (or hard disk drive, HDD)
Hard Disk is a data storage device used in computers and other digital devices to store and retrieve digital information. Unlike RAM, which is volatile and loses data when power is turned off, a hard disk provides non-volatile storage, meaning it retains information even when the device is powered down. Here are the main aspects of a hard disk:
1. Structure and Components
Platters: Hard disks consist of spinning magnetic disks called platters. Data is stored on these platters in the form of magnetic patterns.
Read/Write Heads: Each platter has a read/write head that hovers just above it to read and write data.
Spindle and Motor: A motor spins the platters at high speed (e.g., 5,400 or 7,200 RPM in typical consumer drives, up to 15,000 RPM in enterprise drives).
Controller Board: Controls the movement of the read/write heads and interprets the data for the computer.
2. Functionality
Data Storage: Hard disks store data as binary code (0s and 1s) in specific areas on the platters. When the computer needs to access data, the read/write heads move to the correct location to read or write data.
Permanent Storage: Since it is non-volatile, data on a hard disk remains saved even when the device is turned off, making it ideal for long-term storage of files, applications, and the operating system.
3. Performance
Speed: HDDs are generally slower than newer storage technologies like SSDs (solid-state drives) because they rely on mechanical parts. The spinning platters and moving read/write heads mean that HDDs have slower read and write speeds compared to SSDs.
Capacity: HDDs offer large storage capacities at relatively low costs, making them suitable for storing large amounts of data, like videos, photos, applications, and backups.
4. Types of Hard Disks
Internal HDDs: Installed within desktops or laptops for primary storage.
External HDDs: Connect via USB or other interfaces to provide additional or portable storage.
In summary, a hard disk drive is a storage device that uses spinning magnetic platters to store data long-term, offering reliable, cost-effective storage but slower performance than SSDs.
