Chapter 17: Information and Communication Technology

Information and Communication Technology (ICT): Scientific methods and means to store, process, and transmit vast amounts of information in seconds using electronic equipment.

Flow of Information: Transfer of information from one place to another. Requires: Transmitter (processes input), Transmission Channel (medium like wire, space, or fibre), and Receiver (decodes output).

Methods:

• Wires: Used in telephones (Sound $\to$ Electrical Signal $\to$ Sound).
• Radiowaves: Used in Radio, TV, Cell Phones. Travel at speed of light ($c = 3 \times 10^8$ m/s).
• Optical Fibre: Uses light signals. Principle: Total Internal Reflection. Core has higher index than Cladding. Advantages: High bandwidth, no magnetic interference.

Cell Phone: Radio transceiver (Two-way communication). Network consists of Base Stations (Cells) and MSC (Mobile Switching Centre).

Components:

• Hardware: Physical parts (CPU, Input/Output devices).
• Software: Instructions/Programs (OS, Word Processing).
• Data: Facts (Text, Graphics).
• Procedures: Rules to design/use information system.
• People: Users/Designers.

Storage Devices:

• Primary Memory: RAM (Volatile), ROM (Non-volatile).
• Secondary Storage: Hard Disk (Magnetic, Large capacity), CD/DVD (Optical, Laser technology), Flash Drive (EEPROM).

Units: Bit (0 or 1), Byte (8 bits), KB (1024 B), MB (1024 KB), GB (1024 MB).

Internet: Global network of networks. Services: Web Browsing, Email, E-commerce, Interconnectivity.

Browser: Application to view websites (e.g., Chrome, Firefox).

Email: Electronic transfer of messages. Fast, cheap, and versatile.

Impact: Enhanced education, entertainment, and social connectivity, but risks include crime, piracy, and hacking.