Unit 3: Basic ICT Skills - I Complete Study Guide

1. Introduction to ICT & Core Components

ICT stands for Information and Communication Technology. It encompasses all digital technologies, communication devices, network infrastructure, and software applications that enable society to create, process, transmit, store, and manage information in digital form.

The Three Foundational Pillars

• Information: Raw data that has been structured, calculated, and processed so that it possesses context, meaning, and decision-making value to the receiver (e.g., an annual report card, a consolidated invoice).
• Communication: The interactive transmission and sharing of ideas, voice, messages, and files between two or more parties in a mutually comprehensible form.
• Technology: The scientific methods, electronic hardware circuitry, and software algorithms engineered to automate real-world manual operations.

Role of ICT: Information Technology aims to make critical information accessible at high speeds, with near-zero error rates, across global distances, and at affordable costs.

2. Importance of ICT & 5 Key Daily Developments

ICT has transformed modern society by replacing slow, paper-dependent manual processes with high-speed digital workflows. There is virtually no human activity today that remains untouched by ICT.

5 Groundbreaking Daily Life Developments

1. Online Education & Hybrid Learning: Students attend virtual classrooms via Google Meet or Zoom, access digital libraries, download topic-wise revision notes, and take computerized exams from home.
2. E-Commerce & Digital Marketing: Vendors list catalogs online, market items through social platforms, and deliver goods nationwide, enabling 24x7 commercial transactions.
3. Cashless Digital Payments: Bill payments, tax submissions, school tuition fees, and grocery purchases occur instantaneously through UPI (Unified Payments Interface), internet banking, and mobile wallets.
4. Advance Online Ticketing: Citizens book train tickets (IRCTC), flight seats, intercity buses, and cinema passes directly from home without standing in long queues.
5. On-Demand Cab & Logistics Services: Commuters book cabs and taxis (Uber, Ola) and track parcel deliveries in real time using smartphone GPS applications.

3. ICT Applications Across Modern Sectors

• Education: Interactive smartboards, digital textbooks, virtual laboratory simulations, Diksha, and SWAYAM portals.
• Healthcare & Medicine: Telemedicine consultations, computerized patient records (EHR), robotic surgical tools, CT/MRI scanners, and digital prescription tracking.
• Governance (E-Governance): Online delivery of citizen services, including DigiLocker, Aadhaar authentication, passport applications, and voter registration.
• Banking & Finance: Core banking solutions, ATMs, instant digital transfers (IMPS, NEFT, RTGS), and algorithmic fraud detection.
• Entertainment & Media: 4K on-demand video streaming (YouTube, Netflix), high-fidelity digital audio, and immersive video games.

4. ICT Hardware & Software Tools

ICT Tools are the physical devices, peripheral equipment, software programs, and network connections used to introduce digital technology into educational and professional workflows.

A. Hardware ICT Tools

B. Software as an ICT Tool

Software consists of organized sequences of machine-executable instructions that direct hardware to execute tasks:

• Electronic Spreadsheets: Tabulate numbers, automate complex formulas, and plot dynamic visual charts (LibreOffice Calc, Microsoft Excel).
• Database Management Systems (DBMS): Store, index, update, and retrieve massive volumes of structured records securely (MySQL, MS Access, LibreOffice Base).
• Web Browsers: Client programs used to locate, render, and navigate web pages on the Internet (Google Chrome, Mozilla Firefox, Microsoft Edge).
• Search Engines: Web services that index billions of online documents and display relevant answers based on user search queries (Google, Microsoft Bing, DuckDuckGo).

5. Computer System & The IPO Cycle

A computer is an electronic, programmable data processing machine that accepts raw data as input, processes it under the guidance of stored instructions, produces meaningful information as output, and saves data on storage media for future reference.

The Input-Process-Output (IPO) Cycle

1. Input: Feeding raw facts and user instructions into the computer via input devices.
2. Process: Manipulating, computing, and logically evaluating data inside the CPU.
3. Output: Converting computed binary signals into human-readable text, charts, or sound.
4. Storage: Retaining intermediate or final results permanently on secondary storage drives.

6. Data vs. Information & Types of Processing

Types of Processing Executed by the CPU

• Arithmetic Operations: Core mathematical computations including addition (+), subtraction (-), multiplication (*), and division (/).
• Logical Operations: Decision-making and relational comparisons that evaluate to true or false, such as Equal To (=), Greater Than (>), Less Than (<), and Not Equal To (!=).

7. CPU Architecture: ALU, CU & MU Registers

The Central Processing Unit (CPU) is the "brain" of the computer, responsible for interpreting instructions, coordinating data transfers, and executing computations. It contains three major functional subunits:

• Arithmetic & Logic Unit (ALU): Executes all basic arithmetic operations (addition, subtraction) and logical decisions (evaluating conditional branch conditions).
• Control Unit (CU): The central supervisor and traffic manager. It fetches instructions from main memory, decodes them, and generates timing and control pulses to synchronize all hardware units.
• Memory Unit (MU) / Registers: Small, high-speed memory cells positioned directly inside the processor core. Registers temporarily hold current instruction operands, memory addresses, and intermediate accumulator results.

8. Memory Hierarchy: RAM, ROM & Cache Memory

Computer memory is divided into Primary (Main) Memory and Secondary Storage.

Cache Memory

Cache memory is an ultra-fast static RAM buffer placed directly between the CPU and main system RAM. It stores frequently used instructions and data so the processor does not waste clock cycles waiting for slower DRAM chips. Modern CPUs utilize multi-level caches (L1, L2, and L3 cache).

9. Secondary Storage Devices (HDD, SSD, Optical, Flash)

Secondary storage provides permanent, non-volatile, high-capacity storage for user files and operating system files:

• Hard Disk Drives (HDD): Traditional magnetic storage containing spinning aluminum platters and moving actuator arms. Offers high storage capacity at low cost, but is vulnerable to physical shocks.
• Solid State Drives (SSD): Modern flash memory drives with zero moving parts. SSDs offer 5x to 10x faster read/write speeds, silent operation, low power consumption, and shock resistance compared to HDDs.
• Optical Discs: Read and written using laser beams. Common formats include CD-ROM (~700 MB), DVD-ROM (~4.7 GB single layer), and Blu-ray Disc (~25 GB to 50 GB).
• Flash Memory (Pen Drives & SD Cards): Compact, portable solid-state USB drives and micro-SD cards used in cameras and smartphones.
• Cloud Storage: Remote storage servers accessible over the internet (Google Drive, Microsoft OneDrive, Dropbox) providing accessible, off-site data redundancy.

10. Computer Memory Measurement Units Table

Digital computers store all data in binary (base-2). Multiples of memory are measured in powers of 2 (2¹⁰ = 1024), not powers of 10.

11. Input & Output Peripheral Devices

Essential Input Devices

• Keyboard: Primary alphanumeric data entry device containing function keys, navigation keys, and modifier keys.
• Mouse & Touchpad: Handheld pointing device for selecting, clicking, dragging, and navigating graphic interfaces.
• Flatbed Scanner: Digitizes physical paper documents and photographs into digital images.
• Optical Mark Reader (OMR): Detects pen/pencil marks on objective exam sheets.
• Optical Character Reader (OCR): Converts scanned images of printed text into editable digital characters.
• Magnetic Ink Character Recognition (MICR): Reads specially magnetized numbers printed at the bottom of bank cheques.
• Barcode & QR Code Readers: Scans 1D vertical stripes or 2D matrix codes for rapid product inventory lookup.
• Webcam & Microphone: Captures live video feeds and audio inputs for online meetings and voice recording.

Essential Output Devices

• Visual Display Unit (Monitor): Primary soft-copy output screen (LCD, LED, and OLED).
• Printers: Produces permanent hard copies on paper:
  • Impact Printers: Mechanical pins physically strike an inked ribbon (e.g., Dot Matrix Printer - noisy, inexpensive, used for multi-carbon bills).
  • Non-Impact Printers: Uses toner powder or ink droplets without physical striking (e.g., Inkjet Printers for vibrant photos, Laser Printers for high-speed, razor-sharp documents).
• Plotters: Vector graphics output devices engineered for large architectural blueprints, maps, and engineering schematics.
• Speakers & Headphones: Reproduces digital audio signals into audible sound waves.
• Multimedia Projectors: Projects computer screen output onto large auditoriums or classroom screens.

12. Computer Hardware Ports & Connectors

Ports are physical connection sockets on the computer exterior used to connect peripheral hardware:

13. Hardware vs. Software & Classification

Hardware refers to the physical, tangible parts of a computer system that you can touch and see (e.g., CPU, RAM, keyboard, monitor). Software refers to the intangible collections of instructions, programs, and procedures that instruct hardware on how to execute tasks.

Symbiotic Interdependence: Hardware without software is inert circuitry; software without hardware is an abstract idea that cannot run. They are completely dependent on each other.

14. System Software: OS, Drivers, Translators & Utilities

System Software coordinates internal hardware components and provides a foundational platform on which application software runs.

1. Operating System (OS): The master manager that controls CPU scheduling, RAM allocation, file storage systems, hardware drivers, and user interface (Windows, Linux, macOS, Android).
2. Device Drivers: Specialized software modules that allow the OS to communicate with specific attached hardware devices (e.g., printer drivers, graphics card drivers).
3. Language Translators: Converts human-written source code into binary machine language (0s and 1s):
   • Assembler: Translates assembly mnemonic code into machine code.
   • Compiler: Translates the entire high-level program at once into an executable file (e.g., C, C++). Fast execution speed.
   • Interpreter: Translates and executes high-level source code line-by-line sequentially (e.g., Python). Halts on the first error, enabling faster debugging.
4. Utility Software: Maintenance and housekeeping tools:
   • Antivirus Tools: Scans, quarantines, and destroys malicious virus programs.
   • Disk Cleanup: Scans storage drives to delete temporary junk, system caches, and empty the Recycle Bin.
   • Disk Defragmenter: Consolidates fragmented data sectors on magnetic hard disks for faster read speeds.
   • File Compression: Compresses files to reduce disk footprint and speed up network transmission (7-Zip, WinRAR).

15. Application Software: General vs. Customized

Application Software comprises user-oriented programs designed to perform specific productivity, educational, or business tasks:

• General-Purpose Software: Off-the-shelf software designed for mass public use:
  • Word Processors: LibreOffice Writer, Microsoft Word.
  • Electronic Spreadsheets: LibreOffice Calc, Microsoft Excel.
  • Presentation Tools: LibreOffice Impress, Microsoft PowerPoint.
  • Web Browsers: Chrome, Firefox, Edge, Safari.
• Customized / Tailored Software: Bespoke programs created to meet the unique operational requirements of a particular organization (e.g., School Fee & Report Card System, Hospital Patient Billing, Airline/IRCTC Reservation Systems).

16. Software Licensing: FOSS, Proprietary & Freeware

17. Booting Process: Cold Booting vs. Warm Booting

Booting is the initial automated startup sequence that initializes hardware and loads the operating system kernel from storage into main memory (RAM).

The Booting Steps

1. Electrical power activates the processor and motherboard chipset.
2. CPU executes the BIOS (Basic Input/Output System) stored permanently in ROM.
3. BIOS runs the POST (Power-On Self-Test) to check whether RAM, keyboard, and drives are functioning.
4. The Bootstrap loader locates the boot sector on the SSD/HDD and loads the OS kernel into RAM.
5. The Operating System displays the user desktop or login prompt.

Cold Booting vs. Warm Booting

• Cold Booting (Hard Boot): Turning on the computer from a completely powered-off state by pushing the physical power button on the chassis. Runs complete POST diagnostics.
• Warm Booting (Soft Boot): Restarting the computer while it is already running without turning off the power switch (via Start → Restart, or pressing Ctrl + Alt + Delete).

18. GUI Operating System Interface (Desktop & Taskbar)

Modern operating systems use a Graphical User Interface (GUI) with visual elements:

• Desktop: The background screen workspace that appears after system login.
• Desktop Icons: Small graphic symbols representing applications, shortcuts, or system tools:
  • System Icons: Default system utilities (This PC, Recycle Bin, Network).
  • Shortcut Icons: Distinctive icons with a small curved arrow overlay indicating a direct link to an application or file.
• The Taskbar: The horizontal bar anchored at the bottom edge of the screen:
  • Start Button: Opens the central menu to access installed programs, system settings, and power controls.
  • Search Bar: Quickly finds files, settings, and web answers.
  • Active App Buttons: Displays running windows and pinned favorite apps.
  • Notification Area (System Tray): Shows system time, speaker volume, network Wi-Fi status, battery level, and background utilities.
  • Show Desktop Button: Thin sliver on the far right that instantly minimizes all open windows.

19. Mouse Skills & Essential Keyboard Shortcuts

Primary Mouse Techniques

• Point: Moving the mouse cursor over an on-screen item.
• Single Left Click: Selects or activates an on-screen item.
• Double Click: Rapidly clicks the left button twice to open a folder or launch a program.
• Right Click: Opens a contextual popup menu of relevant actions (Copy, Rename, Properties).
• Drag and Drop: Holding down the left button while moving the mouse, then releasing; used to move files or select text blocks.
• Scroll Wheel: Rolls up or down to scroll through long documents and web pages.

Master Keyboard Shortcuts Table

20. File & Folder Management and Hierarchy

A File is a named collection of related data stored on secondary storage. A Folder (Directory) is a virtual container used to organize, group, and store files and subfolders in a hierarchical tree directory structure.

File Naming Conventions: A filename consists of two parts separated by a dot: [Primary_Name].[Extension]. The primary name identifies the file contents, while the extension denotes the file format and default application.

21. Common File Formats & Extensions Reference

22. File Operations & Wildcard Searches (* and ?)

Step-by-Step File Management

• Creating a Folder: Right-click blank area → New → Folder → Type name → Press Enter.
• Renaming: Select item → Press F2 → Type new name → Press Enter.
• Moving (Cut & Paste): Select file → Ctrl + X → Open target folder → Ctrl + V (Original file is moved).
• Copying (Copy & Paste): Select file → Ctrl + C → Open target folder → Ctrl + V (Duplicate copy created).
• Standard Deletion: Select file → Press Delete (Item moves to Recycle Bin; can be restored).
• Permanent Deletion: Select file → Press Shift + Delete (Item bypasses Recycle Bin completely).

Wildcard Characters in File Searching

• Asterisk (*): Matches any sequence of zero or more characters.
  • *.docx → Finds all Word documents in the folder.
  • sci*.* → Finds all files beginning with "sci" regardless of file extension.
• Question Mark (?): Matches exactly one character at that specific position.
  • test?.txt → Matches test1.txt and testA.txt, but NOT test10.txt.
  • class??.pdf → Matches class09.pdf and class10.pdf.

23. Computer Networking Fundamentals (PAN, LAN, MAN, WAN)

A Computer Network is an interconnection of autonomous computing devices via communication media (cables or wireless signals) to share hardware resources (printers, scanners), files, software, and internet access.

24. Internet, WWW, Web Browsers & Search Engines

The Internet is the worldwide infrastructure of interconnected networks communicating via TCP/IP. The World Wide Web (WWW) is a vast collection of interlinked multimedia web documents accessible over the Internet, invented by Sir Tim Berners-Lee in 1989.

25. URL Anatomy, HTTP vs. HTTPS & Bandwidth

A URL (Uniform Resource Locator) is the unique web address of a document on the Internet.

Example: https://www.techlearners.in/pages/notes/index.html

• https:// → Protocol: Rules used to transmit data.
• www.techlearners.in → Domain Name: The web server address.
• /pages/notes/ → Path: Directory path on the host server.
• index.html → File Name: Specific web page requested.

HTTP vs. HTTPS: HTTP transmits data in clear unencrypted plain text. HTTPS (Secure) encrypts all communication using SSL/TLS encryption, protecting sensitive information like passwords and bank card numbers from eavesdropping.

26. Email Architecture: To, Cc, Bcc, Attachments & Etiquette

Electronic Mail (Email) is a method of sending digital messages and files across computer networks. A standard email address follows the format: username@domain_name (e.g., student@techlearners.in).

Key Email Composition Fields

• To: Primary recipient(s) who are directly addressed and expected to respond.
• Cc (Carbon Copy): Secondary recipients included for informational awareness. All recipients can see every email address in To and Cc.
• Bcc (Blind Carbon Copy): Confidential recipients. Addresses in Bcc are completely hidden from all other recipients (ideal for mass circulars).
• Subject: Concise title summarizing the purpose of the email.
• Attachment: External files (PDFs, images, spreadsheets) attached to the message.

Email Netiquette (Best Practices)

1. Always write a clear, descriptive Subject line.
2. Open with a polite greeting and close with your name and designation.
3. NEVER WRITE IN ALL CAPS—in digital communication, all capital letters is considered shouting.
4. Proofread carefully before clicking "Send".
5. Use "Reply All" sparingly—only when every recipient genuinely requires the reply.

27. Computer Hardware Care & Physical Maintenance

• Dust Cleaning: Wipe computer screens and keyboard surfaces with a dry, lint-free microfiber cloth. Avoid spraying liquids directly onto monitors.
• No Food or Drinks: Strictly keep beverages and snacks away from computer equipment to prevent short-circuits.
• Ventilation: Keep computer chassis and laptop fan exhausts unobstructed (leave 3-4 inches clearance) to prevent overheating.
• Power Surge Protection: Connect desktop computers to an Uninterruptible Power Supply (UPS) to protect against sudden voltage spikes and power failures.
• Safe Removal of USB Drives: Always click "Safely Remove Hardware and Eject Media" before disconnecting flash drives to avoid data corruption.

28. Software Maintenance, Disk Cleanup & 3-2-1 Backups

• Disk Cleanup: Regularly run the OS Disk Cleanup utility to delete temporary cache files, download leftovers, and empty the Recycle Bin.
• Disk Defragmenter: Reorganizes fragmented file sectors on mechanical HDDs so that files are stored contiguously, boosting access speed (Note: SSDs do not need defragmentation).
• Software Updates: Keep the operating system, web browsers, and applications updated with the latest security patches.
• The 3-2-1 Backup Strategy:
  • Keep at least 3 copies of important data (1 primary copy + 2 backups).
  • Store backups across 2 different storage media types (e.g., SSD + external hard drive).
  • Keep at least 1 backup offsite or in secure cloud storage (Google Drive, OneDrive).

29. Cyber Threats & Malware (Virus, Worm, Trojan, Phishing)

Malware (Malicious Software) refers to any program developed to compromise security, steal credentials, or damage digital data:

• Computer Virus (Vital Information Resources Under Siege): Malicious code that attaches itself to an executable program and replicates when the infected host program is executed.
• Computer Worm: Standalone malware that self-replicates across networks without human intervention, consuming massive bandwidth.
• Trojan Horse: Malicious program disguised as attractive or helpful software (like a game or utility) that opens unauthorized backdoors.
• Spyware: Covert software that monitors user activities, tracks browsing habits, and logs keystrokes (keylogger).
• Ransomware: Encrypts user files and locks access, demanding a financial ransom payment for the decryption key.
• Phishing: Fraudulent emails or websites mimicking trusted organizations (banks, schools) to trick users into disclosing passwords, PINs, or credit card numbers.

30. Cyber Safety Rules, Strong Passwords & 2FA

• Strong Password Policy:
  • Use at least 8 to 16 characters in length.
  • Combine uppercase letters (A-Z), lowercase letters (a-z), numbers (0-9), and special symbols (@, #, $, %).
  • Never use personal information (your name, birthdate, mobile number).
  • Use a distinct, unique password for every individual account.
• Two-Factor Authentication (2FA): Adds a second security verification step (like an SMS OTP or mobile authenticator app code) beyond the password.
• Active Antivirus & Firewall: Keep security shields turned on and update virus definitions daily.
• Public Wi-Fi Precaution: Avoid accessing net banking or entering credit card details over unsecured public Wi-Fi networks.

31. Digital Footprint & E-Governance Services

A Digital Footprint is the trail of data you leave behind whenever you use the internet:

• Active Digital Footprint: Data you deliberately share online (social media posts, uploaded photos, blog comments).
• Passive Digital Footprint: Data gathered invisibly without direct user awareness (IP address logs, browsing history, web cookies).

E-Governance: The application of ICT by government bodies to deliver public services transparently and efficiently (e.g., DigiLocker for document verification, UMANG portal, online voter registration, and e-hospital services).