Unit I: Introduction to Computer
Course: Fundamentals of Information Technology
Code: CADSC101
Computer Definition and Characteristics
A computer is an advanced electronic device that takes raw data as input from the user and processes it under the control of a set of instructions (called a program), produces a result (output), and saves it for future use.
Key Characteristics of Computers
- Speed: Computers can perform millions of calculations per second.
- Accuracy: Errors only occur if wrong data is fed (GIGO - Garbage In, Garbage Out).
- Diligence: Unlike humans, computers do not get tired or lose concentration.
- Versatility: They can perform different types of tasks (scientific, business, artistic).
- Storage: Computers can store huge amounts of data for a long duration.
Evolution and Applications
The evolution of computers is marked by generations, moving from vacuum tubes to transistors, integrated circuits, microprocessors, and now Artificial Intelligence.
IT Tools and Applications
Information Technology (IT) tools refer to software and hardware used to create, store, and manage information.
- Education: E-learning platforms and digital classrooms.
- Business: Inventory management and payroll processing.
- Healthcare: Medical imaging and patient record management.
- Banking: Online transactions and ATM services.
Basic Organization of a Digital Computer
The basic structure follows the Input-Process-Output (IPO) cycle.
| Component | Function |
|---|---|
| Input Unit | Accepts data from the outside world and converts it to machine language. |
| CPU | The "Brain" of the computer that processes data. |
| Output Unit | Presents processed information in human-readable form. |
| Storage Unit | Holds data and instructions permanently or temporarily. |
Hardware and Software
Hardware: The physical, tangible parts of the computer that you can touch and see.
Software: A set of instructions or programs that tells the hardware what to do.
Central Processing Unit (CPU) and Memory
Central Processing Unit (CPU)
The CPU consists of three main parts:
- ALU (Arithmetic Logic Unit): Performs mathematical (+, -, *, /) and logical (>, <, =) operations.
- CU (Control Unit): Coordinates the flow of data and instructions.
- Registers: High-speed storage locations within the CPU.
Computer Memory and Storage
- Primary Memory: Volatile (RAM) and Non-volatile (ROM). RAM holds active data, while ROM holds startup instructions.
- Secondary Storage: Used for permanent storage, such as Hard Disk Drives (HDD), Solid State Drives (SSD), and Pen drives.
Input and Output Devices
Input devices allow users to communicate with the computer, while output devices allow the computer to communicate with users.
- Input Devices: Keyboard, Mouse, Scanner, Microphone, Webcam.
- Output Devices: Monitor (VDU), Printer, Speakers, Plotter, Projector.
Types of Software
Systems Software
Software that manages and controls computer hardware so that application software can perform its tasks. Example: Operating Systems like Windows, Linux, and Android.
Application Software
Programs designed to perform specific tasks for users. Example: MS Word, VLC Player, Web Browsers.
Utility Software
Software that helps maintain, configure, or optimize the computer. Example: Antivirus, Disk Cleaners.
Open Source vs. Proprietary Software
| Feature | Open Source | Proprietary |
|---|---|---|
| Source Code | Free and accessible to all. | Locked/Hidden; owned by a company. |
| Cost | Usually free. | Requires a license fee. |
| Examples | Linux, VLC, Firefox. | Windows, MS Office, Photoshop. |
Mobile Apps
Mobile applications (Apps) are software specifically designed to run on mobile devices like smartphones and tablets. They are optimized for touch interfaces and varying screen sizes.
Exam Focus & Tips
- Exam Tip: Be ready to draw the "Basic Organization" block diagram. It is a frequent 5-10 mark question.
- Common Pitfall: Do not confuse RAM (Primary/Volatile) with Storage (Secondary/Non-volatile).
- Mnemonics: CPU parts = ARC (ALU, Registers, Control Unit).
Frequently Asked Questions
Q: What is the difference between Hardware and Software?
A: Hardware is physical (keyboard, monitor); Software is logical/set of instructions (OS, Apps).
Q: Why is the CPU called the "Brain" of the computer?
A: Because it performs all data processing and controls all other parts of the system.