COMPUTER HARDWARE
Definition of Computer Hardware
Computer hardware refers to all the tangible, physical components of a computer system.
These are the parts you can see and touch, as opposed to software, which consists of the
programs and instructions that tell the hardware what to do. Hardware works in
coordination with software to allow a computer to function effectively.
There are two main types:
Internal hardware: Located inside the computer casing (e.g., motherboard, CPU).
External hardware: Connected to the computer externally (e.g., mouse, printer).
Classification of Computer Hardware
Computer hardware is generally grouped into five functional categories:
1. Input Devices
2. Output Devices
3. Processing Devices
4. Storage Devices
5. Communication Devices
Each category plays a specific role in the input, processing, storage, communication, and
output of data within a computer system.
Internal vs. External Hardware
Internal Hardware
These are parts found inside the computer casing. They are crucial for processing and
storing data.
Examples:
Motherboard: Main circuit board where all components connect.
CPU (Processor): Executes instructions.
RAM: Temporary memory used during processing.
Power Supply Unit: Converts electricity to usable power for components.
Hard Drive (HDD/SSD): Stores data permanently.
CMOS Battery: Maintains BIOS settings.
External Hardware
These are devices that are connected outside the system unit and are mainly used for input
and output.
Examples:
Keyboard, Mouse, Monitor, Printer, USB Drives, Speakers, External Hard Drives.
Input Devices
These devices are used to send data or commands into the computer.
Common Input Devices and Their Functions:
Device Description Function
A set of keys arranged in Used to input text, numbers, and
Keyboard
QWERTY layout. commands.
A pointing device with Used to navigate and interact with the
Mouse
buttons and scroll wheel. user interface.
Converts physical documents/images
Scanner Optical input device.
into digital formats.
Captures live video or images for
Webcam Video input device.
communication or recording.
Captures sound for communication,
Microphone Audio input device.
recording, or commands.
Allows users to interact directly with
Touchscreen Both input and output device.
what is displayed.
Stylus/Digital
Used with touchscreens. Writes or draws electronically.
Pen
Biometric Fingerprint, retina, or facial
Used for security and authentication.
Devices scanners.
Output Devices
These are used to display or present data from the computer to the user in a human-
readable format.
Common Output Devices and Their Functions:
Device Description Function
Monitor Displays user interface, applications, and
Visual display unit (LCD/LED).
(Screen) visual content.
Inkjet, laser, or thermal Produces hard copies of digital
Printer
printer. documents/images.
Speakers Audio output devices. Plays music, sounds, or system alerts.
Headphones Personal audio output. Allows private listening of sound.
Enlarges display onto a Used in presentations and media
Projector
wall/screen. sharing.
Specialized printer for large- Used in engineering, mapping, and
Plotter
scale designs. design.
Processing Devices
These are responsible for executing instructions and managing tasks within the computer.
Main Processing Devices and Their Roles:
Device Description Function
Often called the
CPU (Central Processing Executes instructions, performs
"brain" of the
Unit) calculations and manages data.
computer.
Connects and allows
Mainboard containing
Motherboard communication between all
essential circuits.
components.
Controls data flow
Coordinates communication
Chipset between CPU, RAM,
between system components.
and peripherals.
GPU (Graphics Processing Specialized processor Handles rendering of images,
Unit) for graphics. videos, and 3D content.
Northbridge/Southbridge Legacy chipset Northbridge handles
architecture. communication between CPU and
RAM; Southbridge handles I/O
functions.
Storage Devices
These devices store data permanently or temporarily.
Classification of Storage:
a. Primary Storage (Main Memory)
Used for temporary storage of data currently being used or processed.
Device Description Function
RAM (Random Access Volatile memory. Temporarily holds data and instructions
Memory) during use.
ROM (Read Only Non-volatile memory. Stores permanent system instructions
Memory) (like BIOS).
Cache Memory High-speed memory Speeds up processing by storing
near CPU. frequently accessed data.
Registers Small, fast memory in Holds instructions and data being
CPU. processed instantly.
b. Secondary Storage (Permanent Storage)
Used for long-term storage of data and applications.
Device Description Function
Hard Disk Drive Mechanical storage. Stores operating system,
(HDD) applications, and user data.
Solid State Drive Electronic storage. Faster, durable storage compared to
(SSD) HDD.
USB Flash Drive Portable, small memory stick. Used to transfer or store files easily.
Memory Card Small flash memory. Used in mobile devices and cameras.
(SD/TF)
CD/DVD/Blu-ray Optical discs. Store media, software, or backups.
External Hard Portable HDD/SSD. Backup large files or extend
Drive computer storage.
Cloud Storage Online-based storage (e.g., Stores files remotely and accessible
Google Drive). via internet.
Communication Devices
These devices help send and receive data between computers or over networks.
Examples and Functions:
Device Description Function
NIC (Network Connects computer to a local or
Integrated or external card.
Interface Card) internet network.
Internet device with Connects multiple devices to the
Router
multiple ports. internet or each other.
Connects to ISP via Converts digital signals to analog
Modem
telephone/cable. and vice versa.
Connect multiple computers in a
Switch/Hub Network connectivity tools.
LAN.
Wi-Fi Adapter Internal/external. Allows wireless network access.
Short-range wireless Transfers data wirelessly between
Bluetooth Adapter
connection. nearby devices.
Modern Tools That Fall Under Two Categories
1. Smartphone
As Input Device: Touchscreen, microphone, camera for input.
As Communication Device: Internet access, calls, messaging, file sharing.
2. Smartwatch
As Output Device: Displays time, notifications, health info.
As Input Device: Touch input, sensors (motion, heart rate).
3. Interactive Whiteboard
As Input Device: Writes input using a pen or finger.
As Output Device: Displays projection or digital content.
4. Tablet
As Input Device: Touchscreen and stylus.
As Output Device: Displays apps, media, and visuals.
Summary Table: Categories and Devices
Category Devices Function
Input Keyboard, Mouse, Scanner, Send data into the system
Webcam
Output Monitor, Printer, Speaker Present data from the system
Processing CPU, Motherboard, GPU Manage and execute
instructions
Primary Storage RAM, ROM, Cache Temporarily store active data
Secondary HDD, SSD, USB, CD/DVD Permanently store data
Storage
Communication NIC, Router, Modem Exchange data across networks
Conclusion
Computer hardware is the foundation of all computing systems, enabling users to interact
with software and process data efficiently. By understanding the different types of hardware
—input, output, processing, storage, and communication—learners are better equipped to
use, troubleshoot, and maintain computer systems. In modern computing, some devices
combine multiple functions, showing how technology continues to evolve to become more
efficient, compact, and user-friendly.
System Diagnostics and Computer Specifications
Definition of System Diagnostics
System diagnostics refers to the process of checking, analyzing, and verifying the health and
performance of a computer’s hardware and software components. The purpose is to ensure
all parts are functioning properly, to detect faults, and to understand the system's
capabilities by checking its specifications.
Why Perform System Diagnostics?
To know the capabilities of a computer system (e.g., before installing software).
To identify faulty hardware or performance issues.
To monitor system health and performance.
To ensure the system meets the minimum or recommended requirements for
specific applications.
Ways to Access System Specifications
Method 1: Using System Information Tool (Windows)
Press Windows Key + R, type msinfo32, and press Enter.
Opens the System Information window.
Method 2: Using Settings
Go to Settings → System → About.
Displays basic info like Processor, RAM, System type.
Method 3: Using Task Manager
Press Ctrl + Shift + Esc → Click Performance tab.
View CPU, Memory, Disk, GPU, and Network usage and specs.
Method 4: Using Command Prompt
Use command: systeminfo
Gives detailed info on installed OS, memory, and processor.
Method 5: Using Third-Party Tools
Software like CPU-Z, Speccy, or HWMonitor for advanced diagnostics.
Key System Components and Their Specifications
Below is a list of major system components and what their specifications mean, along with
their purpose in the computer.
Component How to Identify Key Specification Purpose
Processor System Info, Task Name, speed (e.g., Executes instructions and
(CPU) Manager Intel Core i5, 2.5 processes data. The faster
the GHz, the quicker the
GHz)
processing.
Temporary memory for
Memory System Info, Task Size (e.g., 8 GB), running programs. More
(RAM) Manager Type (DDR4) RAM allows more
multitasking.
File Explorer → This Permanent storage for
Hard Drive Size (e.g., 500 GB),
PC → Right-click Drive files, OS, and applications.
(HDD/SSD) Type (HDD or SSD)
→ Properties SSDs are faster than HDDs.
Task Manager →
GPU type (e.g., Renders graphics and
Graphics Card Performance → GPU /
NVIDIA GeForce video. Needed for games,
(GPU) DirectX Diagnostic
GTX 1050) video editing, etc.
(dxdiag)
Connects all components.
Model name,
Motherboard Use tools like CPU-Z Determines compatibility
manufacturer
with CPUs, RAM, etc.
Interface between user
Operating Settings → System → Windows version
and hardware; manages
System (OS) About and edition
software and hardware.
Determines compatibility
System Info or
System Type 32-bit or 64-bit with applications and
Settings
drivers.
Firmware used to boot the
BIOS/UEFI System Info Version/date system and configure
hardware.
Power Supply Manual check Wattage (e.g., Supplies power to all
Unit (PSU) (physical) 450W) internal components.
Network Device Manager → Ethernet or Wi-Fi Connects the computer to
Adapter Network Adapters adapter a network or internet.
Converts digital audio into
Device Manager →
Audio driver analog (for speakers) and
Sound Card Sound, video, and
version vice versa (for
game controllers
microphone).
Matching Components to Their Functions
Component Function/Purpose
CPU (Processor) Performs calculations and processes instructions.
RAM (Memory) Temporarily stores data for quick access during active
tasks.
Storage (HDD/SSD) Saves files and the operating system permanently.
GPU (Graphics Card) Handles all graphics rendering and visual output.
Motherboard Serves as the backbone for all connections and data flow.
Power Supply Unit (PSU) Provides regulated electrical power to the computer.
Network Adapter Enables network connectivity (LAN, internet, wireless).
Sound Card Processes audio input/output for speakers and
microphones.
Cooling System Regulates temperature to prevent overheating.
(Fan/Heatsink)
BIOS/UEFI Firmware Initializes hardware during startup and loads the OS.
Sample Output from System Info (Windows)
OS Name: Microsoft Windows 10 Pro
System Manufacturer: HP
System Model: HP ProBook 450 G5
Processor: Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz, 1800 Mhz, 4 Core(s)
Installed Physical Memory (RAM): 8.00 GB
System Type: x64-based PC
BIOS Version: HP Q85 Ver. 01.07.00
Total Physical Memory: 7.88 GB
Available Physical Memory: 3.45 GB
Importance of Knowing System Specifications
Software Compatibility: Ensures software requirements match your system.
Upgrades: Helps identify what hardware can be added or replaced.
Performance Troubleshooting: Find causes of slowness or crashes.
Security and Health Monitoring: Monitor system health to prevent failure.
