1. Introduction to Information and Communication Technology (ICT)
- ICT refers to all technologies used to handle telecommunications, broadcast media, audiovisual processing and transmission systems, and network-based control and monitoring.
- Includes hardware, software, networks, internet, computers, mobile devices, and communication protocols.
- Plays a vital role in modern society for communication, data sharing, and media content creation and distribution.
2. Digital Signal
A digital signal is a discrete, non-continuous signal that represents information using binary (0s and 1s).
Examples of Digital Signals:
- Binary signals (1 and 0)
- Digital audio (e.g., MP3)
- Digital video (e.g., MP4)
- Text and data on computers
- Digital clocks
- Digital control systems (used in robotics, smart homes)
Characteristics of Digital Signals:
- Represented in binary form (0 and 1)
- Less affected by noise
- Can be compressed and encrypted
- Easily stored and transmitted
- More reliable for long-distance communication
3. Analog Signal
An analog signal is a continuous signal that varies over time and can take any value within a range.
Examples of Analog Signals:
- Audio signals from microphones
- Video signals from analog TV
- Temperature readings from analog sensors
- Voltage signals in power lines
- Pressure sensor outputs
Characteristics of Analog Signals:
- Continuous and smooth
- Sensitive to noise and distortion
- Harder to store or transmit over long distances
- Higher quality for natural inputs but less durable
4. Units of Computer Memory
| Unit | Symbol | Size |
| Bit | b | Smallest unit of data (0 or 1) |
| Byte | B | 8 bits |
| Kilobyte | KB | 1024 bytes |
| Megabyte | MB | 1024 KB |
| Gigabyte | GB | 1024 MB |
| Terabyte | TB | 1024 GB |
| Petabyte | PB | 1024 TB |
| Exabyte | EB | 1024 PB |
| Zettabyte | ZB | 1024 EB |
| Yottabyte | YB | 1024 ZB |
5. Differences Between Digital and Analog Signals
| Feature | Analog Signal | Digital Signal |
| Nature | Continuous | Discrete |
| Data Representation | Waveform | Binary (0, 1) |
| Noise Resistance | Less | High |
| Signal Quality | Degrades with distance | Maintained with distance |
| Processing | Complex | Simple and efficient |
6. Signal Transmission
Key Aspects of Signal Transmission:
- Transmitter: Sends the original signal
- Transmission Medium: Medium through which signal travels
- Wires/cables
- Optical fibers
- Wireless channels
- Modulation: Converts data for transmission
- Noise & Interference: Can distort the signal
- Propagation Delay: Time taken for signal to travel
- Receiver: Receives and processes the signal
- Duplexing: Method of sending/receiving simultaneously
- Protocols & Standards: Define communication rules
- Bandwidth: Amount of data that can be transmitted per unit time
7. Components of Digital Communication System
| Component | Function |
| Source | Original data (sound, image, text) |
| Input Transducer | Converts physical input into electrical signal |
| Encoder | Converts signal into suitable format for transmission |
| Modulator | Modifies signal to be carried over medium |
| Channel | Path through which signal travels |
| Demodulator | Converts signal back to original form |
| Decoder | Reconstructs original message |
| Output Transducer | Converts electrical signal back to physical form |
| Output Signal | Final form for human use (e.g., sound, image, text) |
8. Analog Communication
Features:
- Uses analog signals for transmission
- Quality degrades over distance
- More prone to noise
- Harder to multiplex or secure
9. Digital Communication
Features:
- Uses digital signals (0s and 1s)
- Easy to store, compress, and encrypt
- Noise-resistant
- Ideal for modern applications like internet, phones, and digital media
10. Baseband Transmission
Characteristics:
- Uses entire bandwidth of the medium
- No modulation needed
- Best for short-distance communication (e.g., LANs)
11. Broadband Transmission
Characteristics:
- Transmits multiple signals simultaneously
- Uses modulation
- Suitable for long-distance, high-speed internet
12. Advantages of Digital Transmission
- Better noise immunity
- High security through encryption
- Easy storage and retrieval
- High-speed data transfer
- Compact and portable data systems
13. Effect of Digital Technology on ICT
a. Digital Communication:
- Mobile phones, VoIP, Internet calls
b. Digital Media:
- Online news, blogs, eBooks
c. Digital TV:
- High-definition video and sound
- On-demand streaming
14. Use of Digital Technology in Daily Life
Positive Impacts:
- Improved communication (messaging, video calls)
- Access to information (Google, Wikipedia)
- Entertainment (Netflix, YouTube)
- Education & e-learning (MOOCs, Zoom)
- Global connectivity (social media, online gaming)
Negative Impacts:
- Digital addiction
- Privacy concerns
- Cybersecurity threats
- Social isolation
- Misinformation/Fake news
15. Digital Citizenship (Netizen)
A digital citizen uses technology responsibly, ethically, and legally.
🔹 Key Aspects:
- Digital literacy
- Respectful behavior online
- Privacy and security
- Copyright and fair use
- Digital footprint awareness
- Critical thinking
- Online safety
- Balanced technology use
- Responsibility and ethics
- Parental guidance for kids
16. Online Reputation
Your online reputation is how others perceive you based on your digital activity.
Key Aspects:
- Social media posts
- Comments and public interactions
- Online reviews and endorsements
- Respecting others’ privacy
17. Digital Wellbeing
Key Aspects:
- Managing screen time
- Avoiding harmful content
- Balancing online and offline life
- Using parental controls
- Mindful technology use
18. Making Audio and Audio-Visual Materials
Video Editing:
Process of altering video footage to create a final product.
Popular Software:
- Adobe Premiere Pro
- Final Cut Pro
- Davinci Resolve
- Filmora
- CapCut (mobile)
Main Steps of Video Editing:
- Import footage
- Trim and arrange clips
- Add transitions and effects
- Insert titles and captions
- Adjust audio and color
- Export the final video
Video Editing Options:
- Cut/split
- Fade in/out
- Slow motion
- Add background music
- Overlay text
- Green screen effects
also check out :- chapter 1 , chapter 2 , chapter 3 , chapter 4 , chapter 5
