Computer Fundamentals Index

Computer Introduction Types of computer Characteristics of computer Uses of computer History of Computers

Computer Languages

Low Level language Middle level Language High level language

Computer Generation

Generation of Computers Second generation of Computers Third generation of Computers Fourth generation of Computers Fifth generation of Computers

Peripheral Devices

Input devices Output device


Block diagram and basic components Control processing unit (CPU) Software Hardware


Computer Memory Registers Memory Hierarchy RAM Vs ROM Understanding file sizes (Bytes, KB, MB, GB, TB, PB, EB, ZB, YB)

Computer Network

Types of Network Types of Area Networks (LAN, WAN, MAN) TCP Flags

Computer Virus

Computer Virus

Computer Ports

Computer Ports


How to hack a computer How much do Computer Programmers make How does a Computer work How to associate a file with a program How does a computer convert text into binary How does a computer process data into information How to fix a CD-ROM DVD How to fix the no input signal How to install computer memory How to associate a file with a program How to log out of your operating system How do I change my name on Google How to installation or uninstallation Microsoft Paint How to fix a not a valid Win32 application error How to fix missing Microsoft Windows .dll files How to use a computer keyboard How to erase my hard drive and start over How can I test how many words I can write a minute How to shut down a computer How do I open and edit the Windows registry How to edit the registry from the command line How to restart Microsoft Windows How to install a computer processor How to open Microsoft Paint How to fix problems in Windows after installing new software How to enable or disable the preview pane of Microsoft Outlook How to open a Microsoft .wps or Works file in Word How to view the HTML source code in Microsoft Word How to View or Change the Screen Resolution of a Monitor How to Connect and Install a Computer Keyboard How to Delete Temporary Files in Windows 10 How to determine Which Version of Microsoft Office I'm using How to find out how much hard drive space is available How to Fix PC Stuck on Verifying DMI Pool Data How to choose which items show in the notification area How to find similar images using Search by Image How to fix Low Memory and out of memory errors How To Replace the CMOS Battery How do I Update my Antivirus Program How to fix a general protection fault How to Identify problems in the Windows Device Manager How can the Base be Shown How to test if a Website or Web Page is down How Much is 1 Byte, Kilobyte, Megabyte, Gigabyte, etc


Who invented Computer What are the advantages of the Internet? What are the disadvantages of the Internet? Is my computer 64 bit? What is Edge Computing? What is a Router? What is Monitor What is Printer What is a Web Browser What is Microphone What is a Webcam What is PC What is Keyboard What is Motherboard What is WAP What is URL What is a Digital Assistant When was the first Computer Invented What is Modem What is Firmware What is Imperative Programming What is Protocol What is Safe Mode What is Device Driver What is Hybrid Topology What is Mesh Topology What is Procedural language What is a hyperlink What is a Username Who invented the Internet What is Video Card What is Sound Card What is Binary What does Alt+B do What does Alt+D do What does Alt+E do What does Alt+Esc do What does Alt+R do What does ALT + Q do What does Alt + Tab do What is Data Manipulation What is a touch screen What is Back Panel What is Analog Monitor What is AR lens What is an ATX Style Connector What is a File System What is Hard Disk Drive (HDD) What is a boot device What is accessibility What is Line In What is network Interface card (NIC) What is Optical Disk Where can I ask questions on the internet What is Auto Rotate What is CAD (Computer-aided design) What is Cable Modem What is Home Page What is boot menu What is braille reader What is flash memory What is Windows What is Clipboard What is Cyber Warfare What is Myspace Why has my IP address changed What is Jacquard Loom My computer is running slow, what steps can I do to fix it What is a Kensington Lock What is a multicore processor What is automation Are smartphones and tablets computers What is a Login Script What is a Loosely Typed Language What is Multitasking? Why my computer monitor shows no display or black screen What is REM What is Parallelization What is Overtype mode What is open with What is Bracket What is an Online Service What is REM What is Parallelization What is Overtype mode What is open with What is Bracket What is an Online Service What is the Pg Dn Key (Page Down Key) What is the Pg up Key (Page up Key) What is Palmtop Computer What is a Processing Device What is a Print Preview What is the Print Screen Key What can I do if my computer or laptop is lost or stolen What is a Model Number What are the currently available antivirus programs What are Toggle keys What is a Case fan What is a Silicon Chip What is a Slate PC What is a TAB stop What is an Octothorpe What is Task Pane What is Task View What is the svchost.exe file used for in Windows Where can I find free online virus scanners Why am I unable to increase the resolution in Windows What is Autofill When I click my mouse, it sometimes double-clicks What is Scratch What is UDIMM What is MsConfig What is an Expansion Card What is an Executable File What is an Elevated Command Prompt What is an AC Adapter What is AIMBOT What is a Software Suite What is a LED Monitor What does Alt + X do What does alt + space do What does Alt + O do Now that I’ve got a Computer, what can i do What is a Punch Card What is RDIMM What is Select All What is Serial number What is Thermos flask What programs can I use for speech recognition What are the Advantages of Computers What are the Disadvantages of Computers What does Alt + T do What Hardware Device Drivers should be Updated What is a Desktop What is a Ring Topology What is CMOS What is a Directory What is a Mechanical Mouse What is a Plotter What is a Variable What is an Icon What is Data What is HDMI What is Remote What is Right-Click What is SMPS Why does my Laptop not turn on What is a Copyright What is a Cordless Mouse What is a CSV file What is a Joystick What is a Start Button What is a Taskbar What is an Alignment What is an Output Device What is Cat 5 What is Google Chrome What is Post


Difference between hardware and software Difference between multiprocessor and distributed systems Difference between Desktop and Laptop Difference between File and folder Difference between Hard Copy and Soft Copy Open Source Programs vs Closed Source Programs


Quantum Computing Computer Software Autoexec.bat and config.sys info Update an Antivirus Use of Internet Advantages and disadvantages of Email Computing Power Internet Explorer Shortcut Keys Advanced Encryption Standard (AES) Augmented Reality Infrastructure Readiness Check Top 10 Internet tips and tricks Introduction and Features of FoxPro Features of Multimedia Top 10 online services and applications Receiving S.M.A.R.T. status bad backup and replacing error Version Control System Uninstalling Software or Apps in Windows Data Warehouse Increase or decrease font size in Word using keyboard shortcuts Mouse not detected or working in Windows Computer Cleaning Information and Steps Function Keys on Keyboard Windows 7 Alt+Tab won’t stay on top or stick

What is Hard Disk Drive (HDD)?

HDD is an electro-mechanical device that enables the user to store data for future use. The device has magnetic storage that is responsible for storing the information. And, this stored information can be accessed later on; that's why it is considered non-volatile storage.

What is Hard Disk Drive

HDD is an abbreviation for Hard Disk Drive, and it is already installed in the computer when the user purchases it. The HDD is attached with the disk controllers available on the motherboard. The motherboard is the functional unit in the Central Processing Unit (CPU). Most of the data is stored in the HDD, and including the Operating Software and all the other software installed on the system. The user can also store additional computer files such as images, videos, games, etc.

The term non-volatile means that the data is permanent and won't be lost even when the computer is turned off. In 1956, HDD launched the first HDD in the market. It is a fixed device, which means a fixed amount of storage available on the disk. The first computer equipped with a hard drive had storage of less than 1Mb, but the hard drive used now can store up to 1 terabyte of data. The user can also increase the system's storage by attaching an external hard drive to the PC. This is generally used to create backup and provide extra space.

Components of Hard Disk Drive (HDD)

A Hard Disk Drive usually consists of two types of electric motors. It has a spindle motor responsible for rotating the disk and an actuator motor that sets the write/read assembly across the spinning disks, ensuring that the data can be effectively read or written on the memory. The two motors perform different functions. 

What is Hard Disk Drive

An external rotor is placed to the disk in the disk motor and has stator windings. The windings are attached to a place. At the opposite end of the actuator is the head of the support arm. It has multiple read/write pins on it. They have printed circuits attached to these heads that are responsible for amplifying the signals from the electronic devices placed above the actuator motor's pivot. They are made light weighted but stiff at the same time.

The new hard disk drives can be accelerated up to 550g. The actuator motor constitutes a permanent magnet, and enclosed between the magnet is a moving coil used to position the heads and place them to the required position. It also has a metallic plate that supports a squat NIB high flux magnet. The moving coil is placed just below the plate. The coil is also referred to as a voice coil. The coil is connected with the actuator hub, and a second permanent magnet is below it. It is attached to the bottom of the motor plate. While most the HDDs have two magnets, there are some which may have only one magnet.

The voice coil is designed like an arrowhead and is covered with magnetic copper wires on all sides. It is done so that it can be wounded in different shapes without breaking the wire. It also ensures that the wire does not require any external support. The inner coating is made up of an insulating material, and the outermost layer is made up of thermoplastics.

The coil and the arrowhead's sides are suspended in the magnetic field produced by the magnets. The current is passed to the copper wire wrapped around the arrowhead. The direction of the current is radially outward from one side while it is radially inward on the opposite side. The electric current and the magnetic field produce a tangential force. If the magnetic field is kept constant, the force generated from both ends will be equal in magnitude but opposite in direction. There will be no effective force. This will lead to no output. Therefore, the polarity at both ends is kept exactly opposite. That means if one side is the north pole, the other end is the south pole of the same magnet with a radial division. This ensures that the forces add instead of getting cancelled out. The force produced when current is passed from the top of the coil to the other is radial in direction. This does not rotate the head.

The electronic control is responsible for causing the movements in both motors. The disk controller instructs the motor about what and when the data will be read or written from the disk. It is important that both the motor is properly working so that data can be correctly written and read for the memory. 

The feedback from the device is provided by using dedicated segments for the disk.

Furthermore, in server technology, they are concentric circles with real data. The feedback improves the quality of the data stored in the drive-by, managing the signal-to-noise ratio. It can also do so by simply adjusting the voice coil attached to the actuated arm. A Servo motor is also used for the rotation of the disk. The new versions of HDD can schedule the read and write operation effectively on the platter surfaces. It also remaps the media sector that was not properly stored in the first attempt.

Error Detection and Handling 

Modern HDD implements an error correction code (ECC). The technique for error correction is called Reed-Solomon Error Connection. In this, some additional bits are added, and these additional bits are computed using a mathematical formula. For every block of data, the error can be resolved by those bits invisibly. They occupy the space on the drive itself. It prevents the uncorrectable error from occurring. Extra space other than the storage to handle these additional bits of data.

For example: If the storage of the hard disk is 1 Tb that has 512-byte sectors, then it may have additional storage up to 93 Gb for the error correction codes only. In the latest hard drives, these ECC were supplanted by the low-density parity-check codes as they provide better performance and high storage density.

Distinguish Between Hard Disk Drive and Solid-State Drive

1. HDD stands for Hard Disk Drive.1. SSD stands for Solid State Drive.
2. It requires comparatively more time to perform read or write operations on the data stored in HDD.2. It requires comparatively less time to perform read or write operations on the data stored in SSD.
The latency is very high in the HDD.3. The latency in the SSD is comparatively low.
4. The HDD can only perform very few input and output operations in a limited time. It only supports limited operations.4. The user can perform multiple input and output operations in a second.
5. The HDD consists of a rotating disk and a motor; these components add to the weight of the HDD and make it quite heavy.5. The SSD does not have a rotating disk or a motor resulting in comparatively less weight.
6. In the HDD, the data is received and sent in sequential order.6. In the SSD, the data is not sent or received sequentially.
7. When the data is written or read from the HDD, a mechanical movement is performed by the disk and the motor that produces noise.7. The storage does not involve any mechanical moment and does not produce much noise.
8. The Hard Disk Drive is larger in size.8. It requires fewer parts making SSD compact.
9. HDD is cheaper than SSD.9. SSD is more expensive as compared to HDD.
10. It uses an electromagnet to store the data; it can be affected using a magnet, resulting in data loss if kept near a strong magnet.10. A magnet does not affect the data stored inside the SSD.
11. The movement of the motor and disk produces a lot of heat.11. There is no mechanical movement required to read or write the data, so very little heat is produced in SSD.
12. HDD consumes more energy as it requires more electrical energy to perform those mechanical movements.12. It requires very less energy.
13. The time required to perform a boot on HDD is about 30-40 seconds.13. It is more efficient as it requires only 10-13 seconds to perform a boot on SSD.
14. It takes more time to open the file on HDD.14. It is more efficient, and the processing speed is high; it is 30% faster than the HDD.
15. The mechanical motion causes vibrations.15. Without any moving parts, there are no vibrations.

Advantages of Using HDD

  • The HDD is used extensively in personal computers for providing storage.
  • Its cost significantly less, which means this reduces the total cost of the production of the computer.
  • They are easily available in the market. The user can purchase them from the market to increase the storage or replace the existing ones.
  • They are more efficient than optical disks and provide large storage to the user.

Disadvantages of Using HDD

  • As the capacity to store the data increases, it reduces the speed of processing.
  • Due to all the mechanical movement, it produces a lot of noise.
  • It is not energy efficient.
  • Also, it is heavy; thus, it increases the weight of the system.