In this article we providing information regarding latest Navodaya Class 6 Computer Subject April to June Notes 2026.
Navodaya Class 6 Computer Subject April to June Notes 2026
Computer Fundamentals (Part 1) – Detailed Notes
1. Introduction to Computers
A computer is an electronic device that accepts data, processes it, stores it, and gives meaningful output.
Basic Working of a Computer
IPO Cycle
- Input → Enter data using input devices
- Process → CPU processes the data
- Output → Result is shown through output devices
- Storage → Data is saved for future use
2. Brief History of Computers
Computers developed gradually from simple calculating machines to powerful modern systems.
Early Calculating Devices
Abacus
- First calculating device
- Used for counting and arithmetic calculations
- Invented in ancient China
Napier’s Bones
- Invented by John Napier
- Used for multiplication and division
Pascaline
- Invented by Blaise Pascal
- Mechanical calculator for addition and subtraction
Analytical Engine
- Invented by Charles Babbage
- Considered the first concept of modern computer
- Charles Babbage is called the “Father of Computer”
ENIAC
- Full Form: Electronic Numerical Integrator and Computer
- First electronic general-purpose computer
- Very large and consumed huge electricity
3. Generations of Computers
First Generation Computers (1940–1956)
Technology Used
- Vacuum Tubes
Features
- Very large in size
- Generated too much heat
- Slow processing speed
- Consumed high electricity
Examples
- ENIAC
- UNIVAC
Second Generation Computers (1956–1963)
Technology Used
- Transistors
Features
- Smaller than first generation
- Faster and more reliable
- Less heat generation
Third Generation Computers (1964–1971)
Technology Used
- Integrated Circuits (IC)
Features
- Faster processing
- Smaller size
- More storage capacity
Fourth Generation Computers (1971–Present)
Technology Used
- Microprocessors
Features
- Personal computers introduced
- Very fast and compact
- Affordable for home and office use
Examples
- Desktop Computers
- Laptops
Fifth Generation Computers
Technology Used
- Artificial Intelligence (AI)
Features
- Smart computing
- Robotics
- Voice recognition
- Machine learning
4. Characteristics of Computers
| Characteristic | Meaning |
| Speed | Performs millions of calculations quickly |
| Accuracy | Gives correct results |
| Storage | Stores huge amount of data |
| Automation | Works automatically after instructions |
| Reliability | Gives consistent performance |
| Multitasking | Can perform multiple tasks together |
5. Types of Memory
Memory is used to store data and instructions.
A. Primary Memory (Main Memory)
Primary memory is directly connected to CPU.
Features
- Fast access speed
- Temporary storage
- Limited capacity
Types of Primary Memory
1. RAM (Random Access Memory)
Features
- Temporary memory
- Data is erased when power is OFF
- Used during computer operation
Uses
- Running applications
- Opening files
- Gaming and browsing
Types of RAM
- DRAM
- SRAM
Example
When you open:
- MS Word
- Browser
- Video player
They use RAM temporarily.
2. ROM (Read Only Memory)
Features
- Permanent memory
- Data is not erased after shutdown
- Stores startup instructions
Uses
- Booting process
- BIOS storage
Types of ROM
- PROM
- EPROM
- EEPROM
Difference between RAM and ROM
| RAM | ROM |
| Temporary memory | Permanent memory |
| Data lost after shutdown | Data remains saved |
| Faster | Slower |
| Used during work | Used during startup |
B. Secondary Memory
Secondary memory stores data permanently.
Features
- Large storage capacity
- Permanent storage
- Slower than RAM
- Cheaper storage
Examples
| Device | Use |
| Hard Disk | Internal storage |
| SSD | Fast storage |
| Pen Drive | Portable storage |
| CD/DVD | Optical storage |
| Memory Card | Mobile storage |
6. Input Devices
Input devices are used to enter data into the computer.
Common Input Devices
Keyboard
- Used for typing text and commands
Mouse
- Used for clicking and selecting items
Scanner
- Converts paper documents into digital form
Microphone
- Used for voice input
Webcam
- Used for video recording and online meetings
Joystick
- Used in gaming
7. Output Devices
Output devices display the processed result.
Common Output Devices
Monitor
- Displays text, images, and videos
Printer
- Prints documents on paper
Speakers
- Produce sound output
Projector
- Displays output on large screen
Plotter
- Used for engineering drawings
8. Central Processing Unit (CPU)
CPU is called the Brain of Computer.
Functions
- Processes data
- Performs calculations
- Controls all operations
Parts of CPU
ALU (Arithmetic Logic Unit)
- Performs calculations and logical operations
CU (Control Unit)
- Controls all activities
Memory Unit
- Stores instructions temporarily
9. Operating System (OS)
An Operating System is system software that manages computer hardware and software.
Functions of Operating System
| Function | Description |
| File Management | Organizes files and folders |
| Memory Management | Controls RAM usage |
| Device Management | Controls devices |
| User Interface | Allows user interaction |
| Security | Protects system |
10. Types of Operating Systems
Windows Operating System
Examples
- Windows 10
- Windows 11
Features
- User-friendly interface
- Start Menu
- Taskbar
- File Explorer
Linux Operating System
Linux
Features
- Open-source
- Secure and stable
- Used for servers and programming
Popular Linux Versions
- Ubuntu
- Fedora
- Debian
11. Desktop Components
Desktop
Main screen shown after starting computer.
Icons
Small pictures representing files/programs.
Taskbar
Bar usually located at bottom of screen.
Start Menu
Used to access applications and settings.
File Explorer
Used to manage files and folders.
12. Files and Folders
File
A file stores information.
Examples
- Document
- Image
- Video
- Audio
Folder
A folder stores files and subfolders.
13. Common File Extensions
| Extension | File Type |
| .docx | Word document |
| .xlsx | Excel file |
| .pptx | PowerPoint |
| .jpg/.png | Image |
| .mp4 | Video |
| PDF document |
14. Basic File Operations
1. Save
Used to store a file for the first time.
Shortcut
Ctrl + S
Example
Saving a Word document.
2. Save As
Used to:
- Save file with new name
- Save in different location
- Save in another format
Example
Report.docx → Report.pdf
3. Copy
Creates duplicate of selected item.
Shortcut
Ctrl + C
Steps
- Select file
- Right-click → Copy
- Choose location
- Paste
4. Cut
Moves file from one location to another.
Shortcut
Ctrl + X
Difference between Copy and Cut
| Copy | Cut |
| Creates duplicate | Moves original file |
| Original remains | Original removed |
5. Paste
Places copied/cut item.
Shortcut
Ctrl + V
15. Recycle Bin
- Stores deleted files temporarily
- Files can be restored
Permanent Delete
Shift + Delete
16. File Explorer Basics
Functions
- Open files
- Create folders
- Rename files
- Delete files
- Move files
Common Options
- New Folder
- Rename
- Delete
- Properties
17. Important Keyboard Shortcuts
| Shortcut | Function |
| Ctrl + C | Copy |
| Ctrl + X | Cut |
| Ctrl + V | Paste |
| Ctrl + S | Save |
| Ctrl + A | Select All |
| Ctrl + Z | Undo |
| Delete | Delete selected item |
| Alt + Tab | Switch windows |
18. Advantages of Computers
- Fast processing
- Accuracy
- Large storage
- Online communication
- Education and entertainment
19. Limitations of Computers
- Cannot think independently
- Needs electricity
- Depends on instructions
- Security risks (virus/hacking)
20. Quick Revision
Remember
- CPU is brain of computer.
- RAM is temporary memory.
- ROM is permanent memory.
- Input devices enter data.
- Output devices show results.
- Operating System manages computer.
- Save As creates new copy/version of file.
