COMPSCI

Introduction

Computer

An electronic device that accepts data, performs operations, displays results, and stores the data or results as needed.

Hardware

The physical parts, which you can see and touch, are called

Software

refers to the instructions or programs that tell the hardware what to do

Hardware examples

• Mouse

• Monitor

• Motherboard

• Webcam

Software examples

• Internet Explorer

• Microsoft PowerPoint

• YouTube

Types of software

1. Application Software:

• Helps carry out tasks such as creating documents, crunching numbers, and editing photographs.

• Examples: Microsoft Word, Windows Media Player, Paint, Email

2. System Software:

• The computer's operating system, device drivers, and utilities.

• Example: Windows & MacOS.

Data

• Refers to raw facts and figures that the computer processes into meaningful information

• Types:

• Numerical Data: Numbers used for calculations.

• Textual Data: Words, sentences, paragraphs.

• Symbols: Special characters used in data representation.

• Alphabetic Characters: Letters used in text data.

1. Data Storage: Refers to saving data in a storage medium, such as HDD, SSD, or cloud storage.

2. Data Processing: The manipulation of data to generate meaningful information. This can include sorting, calculating, and analyzing data.

3. Data Management: Involves organizing, maintaining, and retrieving data efficiently. This is often handled by Database Management Systems (DBMS) like MySQL, Oracle, and MongoDB.           

Computer Systems

• A computer system is an integrated set of hardware and software designed to process data and produce information.

• Components:

  Hardware, software, data, and users.

Components of a Computer

1. Input Unit

• Function: Consists of input devices attached to the computer that send data to the computer.
  
  

2. Central Processing Unit (CPU)

• Role: Processes all the data; often referred to as the brain of the computer. It performs the required computations.

• Main Components:

1. Arithmetic & Logic Unit (ALU): Handles mathematical operations and logical decisions. It is a fundamental component of the CPU.

2. Control Unit (CU): Manages data flow and coordinates operations by controlling the ALU, memory, and input/output devices, decoding instructions into signals for other components, and overseeing all processes within the computer.

3. Memory Register: Has small and high-speed storage location, and designed for specific functions such as storing data, instructions, or addresses. It serves as the primary storage of the computer, including components like Random Access Memory (RAM).
   
   

• Function: Accepts information from the CPU and consists of output devices that provide processed data from the CPU into a form understandable by users or other devices.

• Devices:

• Monitor: Displays visual output.

• Printer: Produces hard copies of documents.

• Speakers: Output sound.

• Projector: Enlarges visual output for presentations.
  
  3. Output Unit
  - Displays or prints the processed data in user-friendly format

Characteristics of a Computer

1. Speed

• High Processing Speed

• Executes billions of instructions per second.

• Measured in: Hertz (Hz), typically gigahertz (GHz) for modern processors.

2. Accuracy

• Precision: High degree of accuracy in calculations and data processing.    

• Error Sources: Primarily due to hardware malfunctions or software bugs.

3. Automation

• Automatic Operation: Executes pre-programmed instructions without human intervention.

• Example:

• Batch processing of transactions.

4. Storage

• Large Storage Capacity: Can store vast amounts of data.

• Types:

• Primary Storage: RAM (temporary), ROM (permanent).

• Secondary Storage: Hard drives, SSDs, external drives, cloud storage.

5. Versatility

• Multiple Applications: Capable of performing a variety of tasks simultaneously.

• Example:

• Running a web browser, word processor, and music player concurrently.

6. Diligence

• Consistency: Performs repetitive tasks with consistent accuracy and without fatigue.

• Example:

• Data entry, automated testing.

7. Connectivity

• Network Capabilities: Connects to other computers and devices via networks.

• Examples:

• Local Area Network (LAN): Connects computers within a limited area.

• Wide Area Network (WAN): Connects computers over long distances, including the internet.