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Introduction to computers

Site: Embraced Technology
Course: Embraced Technology
Book: Introduction to computers
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Date: Saturday, 13 December 2025, 9:33 AM

Table of contents

1. Types of computers

1.Supercomputers

  • Definition: The fastest and most powerful computers designed to perform complex calculations at extremely high speeds.

  • Use: Weather forecasting, nuclear research, scientific simulations, and space exploration.

  • Example: IBM Summit, Fugaku (Japan).

2. Mainframe Computers

  • Definition: Very large computers used by big organizations to handle and process massive amounts of data.

  • Use: Banking, insurance, government departments, airlines (for booking and transaction processing).

  • Example: IBM Z-series mainframes.

3. Minicomputers (Mid-range computers)

  • Definition: Smaller than mainframes but larger than personal computers. They can serve multiple users at once.

  • Use: Small organizations, laboratories, and departments for shared data processing.

  • Example: DEC PDP series.

4. Microcomputers (Personal Computers)

  • Definition: The most common type of computer designed for individual use.

  • Use: Education, business, entertainment, and home tasks.

  • Examples: Desktops, laptops, and tablets.

5. Embedded Systems

  • Definition: Special-purpose computers built into other devices to control specific functions.

  • Use: Found in washing machines, cars, ATMs, televisions, and mobile phones.

  • Example: Microcontroller inside a microwave oven.

1.1. Category of computers

1. Category by Processing

This classification is based on how computers process data — the type of data handled.

Type Description Example
Analog Computers Process continuous data (like temperature, pressure, or speed). Thermometers, speedometers, scientific measuring instruments.
Digital Computers Process discrete (binary) data (0s and 1s). They perform logical and arithmetic operations. PCs, laptops, calculators.
Hybrid Computers Combine features of analog and digital computers. Used in hospitals and scientific research centers (e.g., monitoring machines in ICUs).

⚙️ 2. Category by Functionality

This classification focuses on the purpose or use of the computer.

Type Description Example
General-Purpose Computers Designed to perform many different tasks. Laptops, desktops.
Special-Purpose Computers Designed for one specific task only. ATMs, traffic control systems, calculators.

🖥️ 3. Category by Size (or Capacity)

This classification is based on the physical size, processing speed, and storage capacity.

Type Description Example
Supercomputer Fastest, largest, and most expensive; used for complex scientific work. Fugaku, IBM Summit.
Mainframe Computer Large and powerful; handles huge data for many users. IBM Z-series.
Minicomputer Mid-sized; supports multiple users in small organizations. DEC PDP series.
Microcomputer Small, personal computer for one user. Desktop, laptop.
Embedded Computer Built into other devices to control operations. Car engine control unit, washing machine.

🧠 4. Category by Generation

This classification is based on technological development over time (hardware and language improvements).

Generation Period Technology Used Example
First Generation 1940–1956 Vacuum tubes ENIAC, UNIVAC
Second Generation 1956–1963 Transistors IBM 1401
Third Generation 1964–1971 Integrated Circuits (ICs) IBM 360
Fourth Generation 1971–Present Microprocessors Personal computers, laptops
Fifth Generation Present and Future Artificial Intelligence (AI), quantum computing Robots, AI-based systems

1.2. video on types of computers

2. components of computer

Hardware

Definition:
Hardware refers to the physical components of a computer system — the parts you can see and touch.

Examples:

  • Keyboard

  • Mouse

  • Monitor

  • CPU (Central Processing Unit)

  • Hard disk, printer

💻 2. Software

Definition:
Software refers to the programs, applications, and instructions that tell the computer what to do and how to do it. It is intangible (cannot be touched).

Examples:

  • Microsoft Windows

  • MS Word, Excel

  • Web browsers (Google Chrome, Firefox)

  • Games, antivirus programs

⚙️ 3. Orgware (or Liveware)

Definition:
Orgware refers to the people, procedures, and organizational methods involved in operating and managing a computer system. It bridges the interaction between hardware and software.

Examples:

  • Computer users and IT staff

  • System procedures and policies

  • Maintenance schedules and workflows

 

 

2.1. parts of hardware

input devices 

output devices

processor

2.2. computer applications

3. Merit and Demerits of computers

1. High Speed

Computers can process data and perform calculations much faster than humans.
Example: A computer can calculate millions of operations per second.

2. Accuracy

Computers perform tasks without errors if the data and instructions are correct.
Example: Used in banking, billing, and scientific research where precision matters.

3. Storage Capacity

Computers can store large amounts of data and retrieve it easily and quickly.
Example: Entire libraries, photos, and records can be stored in a single computer.

4. Automation

Once programmed, a computer can perform tasks automatically without constant human supervision.
 Example: Automatic payroll, online transactions, and manufacturing systems.

5. Versatility

Computers can perform many different tasks — typing documents, playing music, designing, calculating, etc.
 Example: A laptop can be used for both study and entertainment.

6. Reliability

Computers can work continuously for long hours without getting tired or losing concentration.
Example: Servers run 24/7 to keep websites active.

demerits of computers

1.High Cost

Some computers and related equipment (servers, software, networks) are expensive to buy and maintain.
 Example: Setting up computer labs or data centers requires high investment.

2. Unemployment

Automation of tasks by computers can replace human labor, leading to job loss.
Example: Machines replacing cashiers or clerks.

3. Virus and Hacking Risks

Computers are vulnerable to viruses, malware, and hacking, which can damage data or systems.
Example: Data breaches in organizations.

4. Health Problems

Long hours of computer use can cause eye strain, back pain, and stress.
Example: Office workers experiencing computer-related fatigue.

5. Lack of Creativity

Computers can only follow programmed instructions — they cannot think creatively like humans.
Example: They rely on human input to solve new problems.

3.1. computer software

Definition:

Computer software refers to the programs, data, and instructions that tell a computer what to do and how to do it.
It is not physical — you cannot touch or see it directly, but it controls how hardware works.

Types of Computer Software

1. System Software

  • Helps to run and control the computer hardware.

  • Acts as a bridge between the user and hardware.

  • 🧠 Examples:

    • Operating Systems (Windows, macOS, Linux)

    • Utility Programs (antivirus, disk cleanup tools, backup software)

    • Device Drivers

2. Application Software

  • Designed to perform specific user tasks.

  • 🧠 Examples:

    • Microsoft Word → for typing documents

    • Excel → for calculations

    • Photoshop → for image editing

    • Web browsers → for internet access

3. Programming Software

  • Used by programmers to create other software.

  • Provides tools for writing, testing, and debugging code.

  • 🧠 Examples:

    • Programming Languages (Python, C++, Java)

    • Code Editors (VS Code, Notepad++)

    • Compilers and Interpreters

3.2. video on computer software

3.3. operating system

Definition:

An Operating System (OS) is system software that controls and manages all hardware and software in a computer.
It acts as a bridge between the user and the computer hardware, allowing users to interact with the machine easily.

Main Functions of an Operating System

Function Description Example
1. Process Management Controls running programs (processes) and allocates CPU time. Running multiple apps smoothly
2. Memory Management Allocates and monitors computer memory (RAM) among programs. Prevents crashes from lack of memory
3. File Management Manages storage, creation, and access to files and folders. Saving and retrieving documents
4. Device Management Controls hardware devices through drivers (keyboard, printer, etc.). Printing a file
5. User Interface (UI) Provides a way for users to interact with the computer (Graphical or Command-based). Windows desktop, Command Prompt
6. Security Management Protects system resources and data from unauthorized access. Login passwords, user accounts

Types of Operating Systems

Type Description Example
1. Single-user, Single-tasking Allows only one user and one task at a time. MS-DOS
2. Single-user, Multi-tasking One user can run multiple tasks at once. Windows, macOS
3. Multi-user OS Many users can use the system simultaneously. UNIX, Linux
4. Network OS Controls and manages networked computers. Windows Server, Novell NetWare
5. Real-Time OS (RTOS) Processes data instantly for time-sensitive tasks. Used in robots, medical systems
6. Mobile OS Designed for mobile devices. Android, iOS

Examples of Operating Systems

  • Microsoft Windows

  • Linux

  • macOS

  • Android

  • iOS

  • UNIX

Importance of an Operating System

  • Makes computer use easier

  • Controls hardware and software coordination

  • Manages memory and storage

  • Provides security and user management

  • Enables multitasking and networking