Intro-to-Computer (1)

Chapter 1: Introduction to Computer

What is a Computer?

  • Definition: An electronic device that operates under the control of instructions stored in its memory.

  • Functions:

    • Accepts data (input)

    • Processes data according to specified rules

    • Produces information (output)

    • Stores information for future use

Functionalities of a Computer

  • Basic Functions:

    1. Takes data as input.

    2. Stores data/instructions in memory for later use.

    3. Processes data to convert into useful information.

    4. Generates output.

    5. Controls all the previously mentioned steps.

Computer Components

Hardware

  • Definition: The physical elements of a computer system.

  • Includes:

    • Monitor

    • System Unit

    • Keyboard

    • Mouse

    • Modem

    • Printer

    • Speaker

Software

  • Definition: Computer programs with instructions and data.

Computer Units

  • Types of Units:

    • Input Unit

    • Central Processing Unit (CPU)

    • Primary Memory Unit

    • Secondary Storage Unit

    • Output Unit

Input Devices

  • Definition: Any peripheral that provides data and control signals to a computer.

  • Purpose: Translates human-understandable data into a form the computer can process.

  • Common input devices:

    • Keyboard

    • Mouse

    • Touchpad

    • Scanner

    • Webcam

    • Joystick

    • Graphics Tablet

Central Processing Unit (CPU)

  • Definition: The brain of the computer responsible for executing functions and processes.

Components of CPU

  1. Arithmetic Logic Unit (ALU) - Performs arithmetic and logical operations.

  2. Control Unit (CU) - Coordinates all components of the computer and reads instructions.

  3. Registers - Temporary storage for executing data.

Primary Memory

  • Types:

    1. RAM (Random Access Memory):

      • Temporary storage, volatile in nature.

      • Data is accessed randomly.

    2. ROM (Read Only Memory):

      • Permanent storage, non-volatile.

      • Data cannot be modified.

Secondary Memory

  • Purpose: Stores data and programs permanently.

  • Examples:

    • Hard Disk

    • Optical Disk

    • Flash Memory

Differences between RAM and HDD

  • RAM (Main Memory):

    • Temporary storage, faster access, smaller capacity.

    • Contents disappear when power is turned off.

  • HDD (Secondary Memory):

    • Permanent storage, larger capacity, slower access.

    • Contents remain even when power is turned off.

Output Devices

  • Definition: Hardware that communicates the results of data processing.

  • Converts electronic information into a human-readable form.

  • Examples:

    • Monitor (CRT, LCD)

    • Printer (Laser, Inkjet, Dot Matrix)

    • Speakers

    • Projectors

Software Classification

  • System Software:

    • Controls and manages hardware components.

    • Examples: Windows, Linux, Mac OS.

  • Application Software:

    • Used for specific tasks, does not operate the system.

    • Examples: Microsoft Office, browsers, image editors.

Units of Measurement

  • Storage Units:

    • Bit (0 or 1)

    • Byte (8 bits)

    • Kilobyte (1024 bytes)

    • Megabyte (1024 KB)

    • Gigabyte (1024 MB)

    • Terabyte (1024 GB)

Speed Measurement

  • CPU speed measured in Hertz (Hz).

    • 1 Hz = 1 cycle/second

    • 1 MHz = 1 million cycles per second

    • 1 GHz = 1 billion cycles per second

Computer Classification

  • Classifications based on size and power:

    • Personal Computers (PCs)

    • Workstations

    • Minicomputers

    • Mainframes

    • Supercomputers

Mobile Devices

  • Definition: Handheld computers designed for portability.

  • Examples: Tablets, smartphones, netbooks.

Data, Information, and Knowledge

  • Data: Raw facts and figures that are unstructured.

  • Information: Processed data that has relevance.

  • Knowledge: Application and understanding derived from information.

Characteristics of Computers

  • Speed: Fast data processing.

  • Accuracy: High level of accuracy in calculations.

  • Diligence: Consistent performance without fatigue.

  • Storage Capability: Ability to store large volumes of data.

  • Versatility: Can perform multiple tasks effectively.

Computer Viruses

  • Definition: Malicious software designed to disrupt functions.

    • Types:

      • E-mail viruses

      • Trojan horses

      • Worms

Signs of Infection

  • Lack of storage capability

  • Slow execution of programs

  • Unexpected error messages

Prevention Tips

  • Delete suspicious emails.

  • Avoid opening unknown files.

  • Keep antivirus software updated.