Computer Notes · JKSSB / JKPSC / FAA / Junior Assistant
Hardware & Software — Complete Chapter
Elements of Computer, CPU, Storage, Firmware & Humanware
All JKSSB PYQs · New Pattern Statement MCQs · Complete Theory with Exam Tips
📌 Chapter Overview
This is the foundational chapter of Computer Awareness for all JKSSB exams. Questions from this chapter appear across every post — Junior Assistant, FAA, Panchayat Secretary, Wildlife Guard/Inspector, Accounts Assistant and Graduate Level. Master this chapter to build the base for all other computer topics.
// Chapter Contents
1. The Computer System — Big Picture
A computer system is an integrated set of components that work together to receive data (input), process it (process), store it (storage), and produce results (output). Every computer system — from a smartphone to a supercomputer — follows this same IPO cycle.
Scanner, Mic
RAM (working memory)
Speaker, Projector
CD, DVD, Cloud
Four Main Elements of a Computer System
| Element | Definition | Examples |
|---|---|---|
| Hardware | All physical, tangible components of a computer — the parts you can touch, see and feel. Without hardware, software cannot run. | Keyboard, Monitor, CPU, RAM, HDD, Mouse, Printer |
| Software | Set of instructions/programs that tell hardware what to do. Intangible — cannot be touched. | Windows OS, MS Word, Chrome browser, Antivirus |
| Data | Raw facts and figures that are input into the computer for processing. Becomes information after processing. | Numbers, text, images, audio, video files |
| User (Humanware/Liveware) | The people who design, program, operate or use a computer system. The human element. | Programmers, operators, end users, IT professionals |
2. Hardware — Complete Coverage
Hardware refers to all the physical, tangible components of a computer system — parts that you can touch, see, and feel. Hardware requires software to function. Hardware can be classified by function:
Hardware Classification
📥 Input Hardware
Devices that send data into the computer.
Keyboard, Mouse, Scanner, Microphone, Webcam, Joystick, Touchpad, OMR, MICR, Barcode Reader, Light Pen, Digitizer
⚙️ Processing Hardware
The brain — performs calculations and executes instructions.
CPU (Processor), RAM (temporary working memory), Motherboard, Chipset, GPU
📤 Output Hardware
Devices that present processed data from the computer.
Monitor, Printer, Speaker, Projector, Plotter, Headphones
💾 Storage Hardware
Devices that store data and programs.
HDD, SSD, USB Flash Drive, CD/DVD, Memory Card, Magnetic Tape, Cloud Storage
🔌 Communication Hardware
Devices that connect computers to networks.
Network Interface Card (NIC), Modem, Router, Switch, Hub, Ethernet Cable, Wi-Fi Adapter
Motherboard — The Main Circuit Board
The motherboard (also called mainboard or system board) is the main printed circuit board (PCB) in a computer. Everything connects to it — CPU, RAM, storage devices, graphics card, and ports.
| Component on Motherboard | Function |
|---|---|
| CPU Socket | Slot where the processor (CPU) is installed |
| RAM Slots (DIMM) | Slots for installing RAM memory sticks |
| PCI/PCIe Slots | Slots for expansion cards — Graphics card, Sound card, Wi-Fi card |
| SATA Connectors | Connect HDD and SSD storage devices |
| BIOS/UEFI Chip | ROM chip containing firmware for startup (BIOS = Basic Input Output System) |
| CMOS Battery | Small battery that maintains BIOS settings and system clock when powered off |
| Power Connector (ATX) | 24-pin connector where PSU (Power Supply Unit) connects |
| Chipset | Controls communication between CPU, RAM, and peripherals |
| USB Headers | Internal connectors for front panel USB ports |
| Front Panel Connectors | Power button, reset button, LED indicators |
• Motherboard = main circuit board — everything connects here
• BIOS chip is on the motherboard — stored in ROM
• CMOS battery = keeps clock and BIOS settings when power is off
• PCIe slot = for graphics card (GPU)
• SATA = connects HDD/SSD to motherboard
• Hardware is tangible (can touch) | Software is intangible (cannot touch)
3. CPU — The Brain of the Computer
The CPU (Central Processing Unit) is the primary component that executes instructions and processes data. It is often called the "brain" of the computer. Every calculation, logical decision, and data movement is controlled by the CPU.
The CPU consists of three main components:
CPU Key Specifications
| Specification | Description |
|---|---|
| Clock Speed | Measured in GHz (Gigahertz). Indicates how many instruction cycles per second. Higher GHz = faster processor. Modern CPUs: 2–5 GHz range. |
| Cores | Number of independent processing units within one CPU chip. More cores = better multitasking. Dual Core (2), Quad Core (4), Octa Core (8), Hexa Core (6). |
| Cache Memory | Ultra-fast memory inside CPU. L1 (fastest, smallest), L2, L3 (slowest among cache, largest). Stores frequently used data to speed up processing. |
| Word Size / Bus Width | Number of bits CPU processes at once. 32-bit vs 64-bit processors. 64-bit can address more RAM and process larger data chunks. |
| MIPS | Million Instructions Per Second — measures CPU performance/speed |
| FLOPS | Floating Point Operations Per Second — used for scientific computing/supercomputers |
| Overclocking | Running CPU faster than its rated speed — increases performance but generates more heat |
| Thermal Paste | Applied between CPU and cooler to improve heat transfer — prevents overheating |
Fetch-Decode-Execute Cycle (Machine Cycle)
FETCH
CU gets next instruction from RAM
DECODE
CU interprets the instruction
EXECUTE
ALU/CU carries out the instruction
STORE
Result written back to memory
CPU Manufacturers
| Manufacturer | Key Products & Notes |
|---|---|
| Intel | World's largest CPU manufacturer. Desktop: Core i3/i5/i7/i9. Server: Xeon. Budget: Celeron, Pentium. |
| AMD (Advanced Micro Devices) | Main Intel competitor. Desktop: Ryzen 3/5/7/9. Server: EPYC. Budget: Athlon. |
| ARM (Advanced RISC Machines) | Designs CPU architectures (not manufactures chips). Used in smartphones. Apple M1/M2, Qualcomm Snapdragon, Samsung Exynos. |
| Apple | Designs own chips for Mac/iPhone/iPad. Apple M1, M2, M3 (ARM-based). A-series chips for iPhone. |
| Qualcomm | Smartphone processors. Snapdragon series — used in Android flagships. |
• CPU = ALU + CU + Registers
• ALU = does arithmetic and logic operations
• CU = controls and coordinates all operations (does NOT compute)
• Registers = fastest memory (inside CPU)
• Clock speed in GHz | Performance in MIPS
• Dual Core = 2 cores | Quad Core = 4 | Octa Core = 8
• Intel and AMD = main CPU manufacturers
• 32-bit CPU can address max 4 GB RAM | 64-bit = much more
4. Memory & Storage — Complete Coverage
Computer memory is broadly classified into Primary Memory (directly accessible by CPU) and Secondary Memory (storage devices). There is also Cache Memory between CPU and RAM.
Memory Hierarchy — Speed vs Cost vs Size
Primary Memory — RAM & ROM
| Memory | Full Form | Volatility | Description | Used For |
|---|---|---|---|---|
| RAM | Random Access Memory | Volatile — data LOST when power off | Temporary working memory. CPU reads/writes data here while programs run. More RAM = faster multitasking. | DDR4, DDR5 (current standard). 4GB, 8GB, 16GB, 32GB typical sizes. |
| ROM | Read-Only Memory | Non-volatile — data RETAINED without power | Stores firmware (BIOS). Cannot be easily written to by normal programs. Data permanently stored during manufacturing. | BIOS chip on motherboard stores POST and startup code. |
| PROM | Programmable ROM | Non-volatile | Can be programmed ONCE after manufacturing — cannot be erased. | One-time programmable devices |
| EPROM | Erasable Programmable ROM | Non-volatile | Can be erased using ultraviolet (UV) light and reprogrammed. | UV light erases it — used for firmware updates in older devices |
| EEPROM | Electrically Erasable Programmable ROM | Non-volatile | Can be erased and reprogrammed electrically — without UV light. Used in Flash Memory. | Flash drives, SSDs, UEFI BIOS chips use EEPROM technology |
| DRAM | Dynamic RAM | Volatile | Needs to be refreshed thousands of times per second. Cheaper. Used as main system RAM. | Main RAM in computers — DDR4, DDR5 |
| SRAM | Static RAM | Volatile | Does NOT need refreshing — faster but more expensive. Used for Cache memory. | L1/L2/L3 Cache inside CPU |
Secondary Storage — All Types
| Storage Type | Description | Primary Use |
|---|---|---|
| HDD (Hard Disk Drive) | Magnetic storage on spinning platters. Uses read/write heads. Mechanical — moving parts. Capacity: 500GB–20TB. Speed: ~100–200 MB/s. | Desktop PCs, laptop storage, NAS |
| SSD (Solid State Drive) | Flash memory based — no moving parts. Much faster, lighter, more durable than HDD. More expensive per GB. Speed: 500MB/s–7GB/s. | Modern laptops, fast desktops, servers |
| NVMe SSD | Non-Volatile Memory Express — fastest SSD. Uses PCIe interface (not SATA). 3500–7000 MB/s. M.2 form factor. | High-end gaming PCs, workstations |
| USB Flash Drive (Pen Drive) | Portable flash storage in USB form. Plug and play. Capacities: 4GB–1TB. | Data transfer, portable storage |
| Memory Card | Portable flash storage for cameras and phones. SD, microSD, CF cards. | Cameras, smartphones, drones |
| CD (Compact Disc) | Optical disc — 650MB–700MB capacity. Uses laser to read/write. CD-ROM (read only), CD-R (write once), CD-RW (rewritable). | Audio CDs, software distribution (older) |
| DVD (Digital Versatile Disc) | Optical disc — 4.7GB (single layer) or 8.5GB (dual layer). DVD-ROM, DVD-R, DVD-RW. | Movies, software, backup (older) |
| Blu-ray Disc | High-definition optical disc — 25GB (single) or 50GB (dual layer). Uses blue-violet laser. | HD/4K movies, large data backup |
| Magnetic Tape | Sequential access storage — very slow but cheapest per GB for bulk archival. Large capacity (100GB–12TB). | Enterprise backup, archival (still used) |
| Cloud Storage | Data stored on remote servers accessed via internet. Google Drive, OneDrive, Dropbox, iCloud. | Backup, sharing, anywhere access |
Data Storage Units — Conversion
| Unit | Value |
|---|---|
| 1 Bit | Smallest unit of data — 0 or 1 |
| 1 Nibble | 4 bits |
| 1 Byte | 8 bits — stores one character |
| 1 Kilobyte (KB) | 1024 Bytes |
| 1 Megabyte (MB) | 1024 KB = 1,048,576 Bytes |
| 1 Gigabyte (GB) | 1024 MB |
| 1 Terabyte (TB) | 1024 GB |
| 1 Petabyte (PB) | 1024 TB |
| 1 Exabyte (EB) | 1024 PB |
| 1 Zettabyte (ZB) | 1024 EB — total global internet data measured in ZB |
• RAM = Volatile (data lost on shutdown) | ROM = Non-volatile
• SRAM = used for Cache (faster, expensive) | DRAM = used for main RAM (slower, cheap)
• EEPROM = basis of Flash Memory (USB drives, SSDs)
• 1 KB = 1024 Bytes (NOT 1000!) | 1 MB = 1024 KB
• SSD faster than HDD — no moving parts
• NVMe = fastest SSD (PCIe interface)
• Secondary storage = non-volatile — data retained without power
5. Software — Definition, Role & Categories
Software is a set of instructions, programs, and data that tell the computer hardware what to do. Software is intangible — you cannot physically touch it. Without software, hardware is useless. Without hardware, software cannot run.
Role of Software: Software is the intelligence of the computer. It translates user needs into machine instructions, manages hardware resources, provides platforms for applications, and enables all computing tasks.
SOFTWARE CLASSIFICATION TREE
1. SYSTEM SOFTWARE
Manages hardware and provides platform for applications
A) Operating System
Windows, Linux, macOS, Android, iOS
B) Device Drivers
Printer driver, Graphics driver, Audio driver
C) Language Translators
Compiler, Interpreter, Assembler
D) Utility Software
Disk Cleanup, Antivirus, Backup tools, Defragmenter
2. APPLICATION SOFTWARE
Performs specific tasks for the end user
A) General Purpose
MS Word, Excel, PowerPoint, Browser
B) Specific Purpose
Tally (accounting), AutoCAD (design), Photoshop
C) Custom Software
Built for specific organisations — hospital management, payroll
System Software — Detailed
| System Software | Description | Examples |
|---|---|---|
| Operating System (OS) | Core system software — manages all hardware/software resources. Interface between user and hardware. | Windows 11, Linux, macOS, Android |
| Device Driver | Translates OS commands into device-specific instructions. Each hardware device needs its own driver. | HP Printer Driver, NVIDIA GPU Driver, Realtek Audio Driver |
| Compiler | Translates entire high-level source code into machine code at once — creates an executable file. Fast execution after compilation. | GCC (C/C++), javac (Java), Visual C++ |
| Interpreter | Translates and executes high-level code line by line — no separate executable. Slower but easier to debug. | Python interpreter, JavaScript engine, BASIC |
| Assembler | Converts assembly language (low-level) into machine code (binary). | NASM, MASM |
| Linker | Combines multiple compiled object files into a single executable program. | ld (Linux), Microsoft Linker |
| Loader | Loads compiled program into RAM for execution. | Part of OS — not a separate tool usually |
| Utility Software | Performs maintenance and optimization tasks on the computer. | Disk Cleanup, Defragmenter, Backup, Antivirus, File Compression (WinRAR/7-Zip) |
| BIOS/UEFI | Firmware stored in ROM — initialises hardware at startup. First software to run. | AMI BIOS, Award BIOS, UEFI on modern PCs |
Application Software — Detailed
| Category | Purpose | Examples |
|---|---|---|
| Word Processing | Creates, edits and formats text documents. | MS Word, LibreOffice Writer, Google Docs |
| Spreadsheet | Organises data in rows/columns. Calculations, charts. | MS Excel, LibreOffice Calc, Google Sheets |
| Presentation | Creates slideshows with text, images, animations. | MS PowerPoint, Google Slides, Keynote |
| Database Management | Stores, retrieves and manages structured data. | MS Access, MySQL, Oracle, SQLite |
| Web Browser | Accesses and displays web pages on the internet. | Chrome, Firefox, Edge, Safari, Opera |
| Media Player | Plays audio and video files. | VLC, Windows Media Player, iTunes |
| Image/Photo Editor | Creates, edits and manipulates images. | Adobe Photoshop, GIMP, Paint |
| Email Client | Manages email — send, receive, organise. | MS Outlook, Thunderbird, Gmail app |
| Accounting Software | Financial accounting and bookkeeping. | Tally ERP, QuickBooks, SAP |
| CAD Software | Computer-Aided Design — engineering/architectural drawing. | AutoCAD, SolidWorks, CATIA |
| Games | Entertainment software. | PUBG, GTA, Minecraft |
| Antivirus | Detects and removes malware. | Windows Defender, Kaspersky, Quick Heal |
Types of Software Licences
| Licence Type | Description | Examples |
|---|---|---|
| Proprietary / Commercial | Paid software — restricted usage rights. Source code NOT available. Must purchase licence. | Windows, MS Office, Adobe Photoshop |
| Freeware | Free to use but source code NOT available. Cannot modify. | Adobe Reader, VLC (freeware version), Skype |
| Shareware | Free trial for limited time/features — pay to unlock full version. | WinRAR, WinZip (trial) |
| Open Source | Source code freely available — can view, modify, distribute. May be free or paid. | Linux, Firefox, VLC, LibreOffice, Android |
| Free Software (FOSS) | Free to use, study, modify and distribute. Focus on user freedom — not necessarily free of cost. | GNU/Linux, LibreOffice, GIMP |
| Public Domain | No copyright — anyone can use freely without restrictions. | Old government documents, some classic software |
• System Software = manages hardware (OS, Drivers, Compilers, Utilities)
• Application Software = does user tasks (Word, Excel, Browser, Games)
• Compiler = translates ENTIRE program at once → executable
• Interpreter = translates line by line → no executable (Python uses interpreter)
• Open Source = source code available freely (Linux, Firefox, VLC)
• Freeware = free but source NOT available (Adobe Reader)
• Shareware = free trial → pay for full (WinRAR)
• Tally = accounting software | AutoCAD = engineering design
6. Firmware — Software Embedded in Hardware
Firmware is a special type of software that is permanently embedded into a hardware device's memory (ROM or Flash memory). It provides the low-level control and instructions needed for the device to function — essentially the "brain" built into hardware chips.
Firmware sits between hardware and software in the computing hierarchy. It is more permanent than software (regular programs) but more flexible than pure hardware circuits.
Firmware vs Software vs Hardware — Key Differences
| Type | What It Is | Storage | Changeability | Examples |
|---|---|---|---|---|
| Hardware | Physical components — circuit boards, chips, wires | Cannot be changed without physical replacement | Cannot be changed | Monitor, CPU, Keyboard |
| Firmware | Software embedded permanently in hardware chips | Stored in ROM/Flash — very rarely updated | Updates require special tools (flashing) | BIOS, Router firmware, Printer firmware |
| Software | Programs installed on a computer — run on hardware | Stored on HDD/SSD — changes frequently | Easy to install, update, uninstall | Windows, MS Word, Games, Apps |
Examples of Firmware
| Firmware Type | Function | Exam Note |
|---|---|---|
| BIOS / UEFI | Stored in ROM chip on motherboard. First software to run when computer starts. Initialises hardware. Controls boot sequence. | BIOS update = 'flashing the BIOS' — risky if interrupted |
| Router Firmware | Stored in router's flash memory. Controls all networking functions, security settings, Wi-Fi protocols. | Routers receive firmware updates to patch security vulnerabilities |
| Printer Firmware | Stored in printer's ROM. Controls printing engine, print head, paper feeding. | Printer firmware updates fix bugs and add features |
| Hard Drive Firmware | Stored on a small chip in the HDD. Controls read/write operations, error correction, spin speed. | Rarely updated — sophisticated firmware attacks can be very persistent |
| Mobile Phone Firmware | Stored in flash memory of phone. Controls hardware-software interface at the deepest level. | Android updates include firmware components |
| Smart TV Firmware | Controls TV hardware — channel scanning, HDMI, display settings. | Smart TVs receive firmware OTA (Over The Air) updates |
| Embedded Systems Firmware | Microcontrollers in appliances. Washing machine drum control, microwave timer, car ECU. | Often permanent — cannot be updated by user |
Firmware Update (Flashing)
Updating firmware is called flashing. It is riskier than updating regular software because if interrupted (e.g., power failure), the device can become permanently unusable (bricked). Common methods:
| Method | Description |
|---|---|
| BIOS Flashing | Update BIOS via USB drive or Windows-based tool. Must not interrupt power. |
| OTA (Over The Air) | Firmware downloaded and installed automatically over the internet — used in smartphones, routers, smart TVs. |
| In-Circuit Programming | Firmware loaded via special programmer hardware — used in manufacturing/repair. |
• Firmware = software stored in ROM/Flash memory inside hardware
• BIOS = most commonly asked firmware example
• Firmware is more permanent than software but less permanent than hardware circuits
• Updating firmware = 'flashing'
• If flashing fails → device gets 'bricked' (permanently unusable)
• Firmware controls hardware at its lowest level
• Embedded systems (washing machines, microwaves) run entirely on firmware
7. Humanware (Liveware / Peopleware)
Humanware (also called Liveware or Peopleware) refers to the human element of a computer system — the people who design, develop, operate, maintain and use computers. Without humans, even the most powerful hardware and software combination is purposeless.
Humanware is sometimes listed as the fourth or fifth component of a computer system (alongside Hardware, Software, Data, and Firmware). It is the only component that brings purpose and intelligence to the system.
Categories of Humanware
| Category of Humanware | Role & Function | Key Responsibilities |
|---|---|---|
| System Analyst | Analyses user requirements and designs computer-based solutions. Bridge between users and developers. | Analyse business problems, create technical specifications, recommend system improvements |
| Software Developer / Programmer | Writes, tests, and maintains software code. Creates applications and system software. | Develop apps, write code (Python, Java, C++), debug programs, maintain existing systems |
| Database Administrator (DBA) | Designs, implements and maintains databases. Ensures data security, performance and backups. | Manage MySQL/Oracle databases, optimise queries, set user access permissions, backups |
| System Administrator (SysAdmin) | Manages and maintains computer networks and servers in an organisation. | Install OS updates, manage user accounts, monitor server health, network troubleshooting |
| Network Engineer | Designs, implements and manages computer networks. | Set up routers/switches, configure VPNs, monitor network performance, ensure connectivity |
| IT Manager | Oversees an organisation's IT infrastructure, team and strategy. | Budget planning, staff management, technology strategy, vendor management |
| Computer Operator | Runs and monitors computer systems and equipment in real-time. | Monitor system performance, run batch jobs, basic troubleshooting, backups |
| End User | The common person who uses software for specific tasks — not necessarily technically skilled. | Office workers using MS Office, students using educational software, customers using banking apps |
| IT Trainer / Educator | Teaches computer skills to others. | Corporate training, schools, coaching institutes, online courses |
| Cybersecurity Professional | Protects computer systems and networks from digital attacks. | Penetration testing, security audits, incident response, firewall management |
Why Humanware Matters
🎯 Design & Purpose
Humans decide WHAT the computer should do and WHY. Hardware and software are tools — humans give them purpose and direction.
⚙️ Operation & Maintenance
Without human operators, systems cannot be monitored, updated, or fixed. Regular maintenance requires human expertise.
🔐 Security & Ethics
Humans are both the strongest and weakest link in security. Cybercrime requires both human attackers and human defenders.
• Humanware = Liveware = Peopleware — all three terms mean the same thing
• Humanware = the human element of a computer system
• Without humanware, hardware and software serve no purpose
• System Analyst = bridges users and developers
• DBA = Database Administrator
• SysAdmin = manages servers and networks
• End user = common person using computer for daily tasks
8. All JKSSB PYQs — Hardware, Software, CPU, Storage, Firmware & Humanware
Actual questions from JKSSB exams across all posts.
9. New Statement-Based Pattern MCQs
JKSSB 2026 new pattern — evaluate multiple statements simultaneously.
⚡ Quick Revision — Most Exam-Tested Facts
Hardware & Software
- Hardware = physical (tangible)
- Software = intangible programs
- Firmware = software in ROM chip
- Humanware = people using computers
- IPO = Input → Process → Output
- Open Source = source code available
- Freeware = free, no source code
CPU
- CPU = ALU + CU + Registers
- ALU = arithmetic + logical ops
- CU = controls/coordinates (no calc)
- Registers = fastest memory
- Clock speed = GHz
- Cores: Dual=2, Quad=4, Octa=8
- Fetch → Decode → Execute → Store
Memory & Storage
- RAM = volatile, temporary
- ROM = non-volatile, permanent
- SRAM = Cache | DRAM = Main RAM
- EEPROM = basis of Flash drives
- 1 KB = 1024 Bytes
- SSD faster, HDD uses magnetic platters
- NVMe = fastest SSD (PCIe)
Software Types
- System: OS, Drivers, Compilers
- Application: Word, Excel, Browser
- Compiler = whole program at once
- Interpreter = line by line (Python)
- Firmware: BIOS, Router, Printer
- Humanware = Liveware = Peopleware
- BIOS firmware = flashing to update
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