1. Introduction to Computing

• Data vs. Information Data: Raw, unorganized facts (e.g., numbers, text).
  Information: Data that has been processed into a meaningful form (e.g., a chart, a report).
• Generations of Computers 1st Gen (1940s-50s): Vacuum Tubes. Very large, slow, and expensive.
  2nd Gen (1950s-60s): Transistors. Smaller, faster, and more reliable.
  3rd Gen (1960s-70s): Integrated Circuits (ICs). Computers became smaller and accessible to more businesses.
  4th Gen (1970s-Present): Microprocessors. Led to personal computers (PCs).
  5th Gen (Present/Future): Artificial Intelligence (AI) and Quantum Computing.
• Classification by Data Representation Analog: Represents data in a continuous form (e.g., a thermometer).
  Digital: Represents data in discrete digits (0s and 1s).
  Hybrid: Combines features of both analog and digital computers.
• Classification by Purpose General-Purpose: Can perform a wide variety of tasks (e.g., PC, smartphone).
  Special-Purpose: Designed to perform a specific task (e.g., calculator, ATM).

2. Components of a Computer

• Computer Hardware The physical parts of a computer you can touch.
  • CPU (Central Processing Unit): The "brain" of the computer; executes instructions.
  • Primary Memory: Main memory, directly accessible by the CPU (RAM, ROM).
  • Secondary Storage: Long-term storage (HDD, SSD, USB drive).
  • Input Devices: Send data to the computer (keyboard, mouse).
  • Output Devices: Receive data from the computer (monitor, printer).
• RAM vs. ROM

  Feature	RAM (Random Access Memory)	ROM (Read-Only Memory)
  Volatility	Volatile (loses data when power is off)	Non-Volatile (keeps data without power)
  Operation	Read and Write	Read-Only
  Purpose	Temporary storage for running programs	Permanent storage for firmware (e.g., BIOS)

• Computer Software A set of instructions that tells the hardware what to do.
  • System Software: Manages the computer hardware (e.g., Operating System, Drivers).
  • Application Software: Performs specific tasks for the user (e.g., Chrome, MS Word, Photoshop).
• Operating System (OS) Functions Manages memory, processes, files, and input/output devices. It provides a user interface.

3. Applications of Computers

• Key Application Areas Education: E-learning platforms, online research.
  Business: Data processing, e-commerce, communication.
  Healthcare: Patient records, medical imaging, diagnostics.
  Entertainment: Video games, streaming services, special effects.
  Science: Simulations, data modeling and analysis.