Definition of a computer: what is it and how does it work?

A computer is a device that can process data, perform calculations, and communicate with other devices or systems.

It consists of hardware, which refers to the physical components that make up a computer, and software, which refers to the instructions that tell the hardware what to do.

Origin of the word computer

Definition of a computer: what is it and how does it work? STUDYSHOOT

The word “computer” comes from the Latin word “computare,” which means “calculation.” It has been used since the 16th century to describe people or machines that perform mathematical operations.

The first known use of the word "computer" to describe a machine was in 1613, when it was used to describe a device called the "Thorowgood Calculator", which was a mechanical calculator that could perform addition and subtraction.

Over time, the word “computer” became associated with more and more advanced devices that could perform a wide range of tasks, not just mathematical operations. Today, the term “computer” usually refers to electronic devices that can process and store large amounts of data and perform complex operations, such as desktop computers, laptops, and servers.

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Development of computers

Computer development stations

The development of computers has a long and complex history, and many people and organizations have contributed to its development. The invention of the computer cannot be attributed to one person or group.

The abacus was one of the oldest known devices that can be considered a precursor to the modern computer, and it is a calculating tool that has been used for thousands of years. In the nineteenth century, many mechanical devices were developed that could perform calculations automatically, such as the difference engine and the analytical engine.

These devices were designed by Charles Babbage and Ada Lovelace, and while they were not built during their lifetime, they laid the foundation for the development of modern computers.

During the twentieth century, electronic computers were developed that used electronic circuits and switches to perform calculations. Early computers were large, expensive, and difficult to use, but they paved the way for the development of smaller, more powerful, and more user-friendly computers.

Among the key figures and organizations involved in the development of computers are John Atanasoff and Clifford Perry, who developed the first electronic computer. Alan Turing, who made significant contributions to the field of computer science; And the team at IBM that developed the first personal computer, the IBM PC. In the 21st century, computers have continued to develop at a rapid pace, with the proliferation of devices such as smartphones, tablets, and wearables.

From the inventor of the computer

From the inventor of the computer

The invention of the computer is the result of a collective effort and technical development over decades, and therefore cannot be attributed to one person. However, there are many scientists and inventors who played crucial roles in the development of the computer as we know it today. Here are some of the main characters:

Charles Babbage (1791-1871)

  • Babbage is considered one of the first to introduce the idea of ​​an automatic calculating machine. He proposed the design of the Analytical Engine, which would have been the first programmable mechanical computer, had it been fully built.

Alan Turing (1912-1954)

  • Turing is considered the "father of modern computing." He presented a mathematical model of computing through what is now known as a “Turing machine,” a theoretical concept of a machine capable of performing any mathematical operation that can be described by an algorithm.

John von Neumann (1903-1957)

  • Von Neumann introduced a design for a computer that relied on storing programs in computer memory, a concept that most computers use today. This design is known as the “von Neumann architecture.”

Konrad Zuse (1910-1995)

  • A German engineer designed the first programmable electromechanical computer, called the Z3, in 1941. The Z3 is considered the first computer to operate entirely using transistors and electrical circuits.

Howard Aiken (1900-1973)

  • He led the project to develop the Harvard Mark I electronic computer, which was one of the first programmable computers in the United States.

John Presper Eckert and John Moakley

  • They led the development of the first large digital electronic computer, ENIAC, which was completed in 1945 and was the first comprehensive, programmable digital electronic computer.

Impact of World War II

  • Efforts to develop computing accelerated during World War II due to the need for complex and fast calculations in the military and scientific fields.

Computer mechanism

Computer mechanism

Computer machinery relies on several basic components that work together to process and store data and execute program commands. Here is a brief explanation of these components and how the computer works:

Basic components of a computer:

  1. central processing unit (CPU):
    • Also known as processor. It is considered the brain of a computer where arithmetic and logical operations are performed. Consisting of:
      • Arithmetic and logic unit (ALU): It performs arithmetic operations (such as addition and subtraction) and logical operations (such as comparisons).
      • Control unit: Supervises the execution of instructions by controlling the flow of data between different parts of the computer.
  2. Memory:
    • RAM: Used to temporarily store data and instructions needed by the CPU during execution. It is characterized by high access speed.
    • Permanent memory (ROM): Contains fixed, unchanging instructions that are often essential to the operation of the device.
  3. I/O Units:
    • input units: Includes devices used to enter data into the computer such as keyboard, mouse, and scanner.
    • output units: Includes devices used to display data from the computer, such as monitors, printers, and speakers.
  4. Storage unit:
    • It is used to store data permanently. These include hard disks (HDD), solid-state hard disks (SSD), and optical disks (CD/DVD).
  5. Motherboard:
    • The main board that connects all of the computer's components together, including the central processing unit, memory, input and output units, and storage units.

How a computer works:

  1. Fetching:
    • The controller fetches instructions from memory (RAM) to the CPU.
  2. Decoding:
    • The control unit decodes the instructions to understand what needs to be done. Instructions are translated into a series of signals that the CPU can execute.
  3. Executing:
    • The arithmetic and logic unit performs the required arithmetic or logical operations according to instructions.
  4. Storage:
    • The results are stored in memory or sent to output units for display.

Basic Cycle:

  • This process is known as the Fetch-Decode-Execute-Store Cycle, and this cycle is repeated continuously to execute computer programs.


  • Software is a set of instructions that tells a computer what to do. Includes the operating system (such as Windows or Linux), applications (such as word processors, graphics programs), and middleware.

Computer history and generations

Computer history and generations

The history of computers can be divided into several distinct generations, each characterized by significant technological developments and innovations:

  1. First generation (1940-1956): The first computers were large and expensive, and used vacuum tubes to process data. They were used primarily for scientific and military purposes.
  2. Second Generation (1956-1963): The second generation of computers introduced the use of transistors, which were smaller and more reliable than vacuum tubes. These computers were still large and expensive, but they were faster and more powerful than first generation computers.
  3. Third Generation (1964-1971): The third generation of computers introduced the use of integrated circuits, which reduced the size and cost of computers. These computers were more easy to use, with the development of operating systems and the use of computer keyboards and monitors.
  4. Fourth Generation (1972-1983): The fourth generation of computers saw widespread adoption of microprocessors, which allowed computers to be smaller and more affordable. This led to the development of personal computers and the growth of the home computer market.
  5. The Fifth Generation (1984-1991): The fifth generation of computers marked the beginning of the modern era of computing, with the development of artificial intelligence, the Internet, and the use of graphical user interfaces (GUIs).
  6. Sixth Generation (1991-present): The sixth generation of computers witnessed the continued development of the Internet, the growth of mobile computing, and the rise of cloud computing. It has also seen the development of new technologies such as virtual reality and the Internet of Things (IoT).

Types of computers today

Types of computers today

Today's computers vary greatly to meet different needs. Here are the main types:

1. Laptops:

  • Portable and lightweight: Like the MacBook Air, suitable for commuting and daily work.
  • High performance: Like MacBook Pro and Dell XPS, suitable for heavy work and graphic design.

2. Desktops:

  • traditional: Such as Dell OptiPlex, for office work and daily use.
  • Designed for gaming: Such as Alienware and HP Omen, for gaming and high performance.

3. Mini PCs:

  • Such as Intel NUC and Mac MiniSmall in size, used as media center devices or in environments that require limited space.

4. 2-in-1 PCs:

  • Like Microsoft Surface Pro: Combines the functions of a laptop and tablet.

5. Tablets:

  • Such as iPad and Samsung Galaxy Tab: Used for browsing, entertainment and education.

6. Servers:

  • Such as IBM Power Systems and Dell PowerEdge: It is widely used in network management and data storage.

7. Supercomputers:

  • It is used for scientific research and solving complex computational problems.

8. Embedded Computers:

  • Found in smart devices such as cars and home appliances.

These types meet diverse needs from personal and recreational use to advanced scientific and industrial uses.

Computer operating system

Computer operating system

An operating system (OS) is software that controls the overall operation of a computer. It manages computer hardware resources, such as CPU, memory, and storage devices, and enables users to interact with the computer through a user interface.

The operating system is the first program that runs when you turn on the computer, and it is responsible for starting the programs and other processes that the computer needs to run. It also provides a platform for running other programs, and it manages communication between hardware and software.

There are several types of operating systems, including:

  1. Desktop operating systems: Desktop operating systems are designed for use on desktop and laptop computers. Examples include Microsoft Windows و MacOS And Linux.
  2. Mobile Operating Systems: Mobile operating systems are designed for use on smartphones and tablets. Examples include Android and iOS.
  3. Server operating systems: Server operating systems are designed for use on servers, which are computers used to host websites, databases, and other services on a network. Examples include Windows Server and Linux.
  4. Embedded operating systems: Embedded operating systems are designed for use on devices that are not primarily used as computers, such as routers, printers, and industrial control systems. Examples include VxWorks and QNX.
  5. Real-time operating systems: Real-time operating systems are designed for use in systems that require immediate data processing, such as aircraft control systems and medical equipment. Examples include VxWorks and QNX.

The difference between data and information in a computer

The difference between data and information in a computer

In a computer, data refers to the raw facts and figures that are processed and stored by the computer. It is the raw material on which the computer works, and it can be in the form of numbers, text, images, or other types of media.

Information, on the other hand, is the meaning derived from data. It is the context and interpretation of data that gives it meaning and value. For example, a list of numbers may be data, but if those numbers represent sales figures, they become information about the company's sales performance.

In other words, data is the raw material used to create information. The computer processes and processes data to extract meaning and value, and this processed data is referred to as information.

For example, a spreadsheet containing a list of numbers may be data, but when those numbers are used to calculate the mean, median, or standard deviation, they become information that can be used to make decisions or draw conclusions. Likewise, a database containing a list of names and addresses may be data, but when this data is used to build a mailing list or to conduct research, it becomes useful and meaningful information.

What are the types of computer applications?

What are the types of computer applications?

There are many types of computer applications or “apps” that can be used to perform a wide range of tasks. Some common types of computer applications include:

  1. Productivity Apps: Productivity apps are designed to help users manage their time, tasks, and resources more effectively. Examples include word processing software, spreadsheet software, and project management software.
  2. Communication Apps: Communication applications are designed to help users communicate with others using text, voice, or video. Examples include email clients, messaging applications, and video conferencing software.
  3. Multimedia Applications: Multimedia applications are designed to allow users to create, edit, and share audio, video, and images. Examples include image editing software, video editing software, and audio production software.
  4. Internet and Web Applications: Internet and web applications are designed to allow users to access the Internet and interact with online content. Examples include web browsers, search engines, and social media platforms.
  5. Gaming Applications: Gaming applications are designed to provide entertainment and allow users to play games on their computers. Examples include casual games, such as puzzles and matching games, as well as more complex games, such as role-playing games and first-person shooters.
  6. Education and Reference Apps: Education and reference apps are designed to provide users with information and learning resources. Examples include language learning software, educational games, and digital dictionaries.
  7. Security applications: Security applications are designed to protect your computer or device from viruses, malware, and other threats. Examples include antivirus software, firewall software, and password managers.
  8. Utility Applications: Utility applications are designed to perform specific tasks or functions that are useful to the user. Examples include file compression programs, backup programs, and system optimization tools.

Computer uses

Computer uses

Computers are used in many fields and applications covering a wide range of daily and professional activities. Here are some of the main uses of a computer:

1. Education:

  • Students and teachers can use computers to access online educational resources, attend online classes, and conduct academic research.
  • Using e-learning platforms and smart learning applications to improve the learning experience.

2. Business and management:

  • Programs such as spreadsheets (Excel) and project management software (such as Microsoft Project) are used for business organization and financial management.
  • Use email, online meeting software (such as Zoom and Microsoft Teams) to communicate with employees and clients.

3. Health and medicine:

  • Storing and managing patient data electronically.
  • Using computer programs to analyze medical images such as X-rays and magnetic resonance imaging (MRI).

4. Entertainment and media:

  • Play various games ranging from simple games to advanced games with high-quality graphics.
  • Play and edit music and videos using programs like Adobe Premiere and Final Cut Pro.

5. Engineering and design:

  • Use programs such as AutoCAD and SolidWorks to design engineering and architectural models.
  • Use programs such as Adobe Photoshop and Illustrator to design graphics and logos.

6. Research:

  • Using computers to simulate and model scientific phenomena such as climate change and chemical reactions.
  • Use programs such as MATLAB and R to analyze big data and extract scientific results.

7. E-Commerce:

  • Establishing and managing online stores such as Amazon and eBay to buy and sell products online.
  • Using electronic payment systems such as PayPal to conduct financial transactions over the Internet.

8. Security and defense:

  • Using computers to monitor and analyze security and intelligence data.
  • Management and operation of advanced defense systems and drones.

9. Government administration:

  • Providing government services to citizens online, such as renewing licenses and paying taxes.
  • Storing and managing national data and statistical information.

10. The art and literature:

  • Use word processing programs such as Microsoft Word to write and edit texts.
  • Create digital art using programs such as Adobe Illustrator and Corel Painter.

Computer is a versatile tool that can improve efficiency and productivity in various fields. Whether in education, business, health, entertainment, engineering, scientific research, e-commerce, security, government, or art and literature, the computer is an essential part of modern life.

Pros and cons of computers

Pros and cons of computers

Like any technology, computers have positive and negative aspects. Some pros and cons of computers include:


  1. Increased Productivity: Computers can perform tasks quickly and accurately, allowing users to complete work more efficiently.
  2. Access to Information: Computers provide access to a vast amount of information, allowing users to research and learn about any topic.
  3. Communication and Collaboration: Computers allow users to communicate and collaborate with others, regardless of location.
  4. Entertainment: Computers provide access to a wide range of entertainment options, such as games, movies, and music.
  5. Convenience: Computers make it easy to perform tasks, such as banking, shopping and paying bills, from anywhere.


  1. Dependence: People may become overly dependent on computers and may have difficulty functioning without them.
  2. Security risks: Computers are vulnerable to security threats, such as viruses, malware, and hacking.
  3. Loss of privacy: Computers can collect and store personal information, raising privacy concerns.
  4. Health risks: Prolonged use of computers can lead to health problems, such as eye strain, neck and back pain, and carpal tunnel syndrome.
  5. Social isolation: Reliance on computers may lead to social isolation and lack of face-to-face interaction.

Comparison between laptop and desktop computer

Here is a comparison between a laptop and a desktop computer in terms of several main aspects:

1. Size and weight:

  • Laptop:
  • Size and weight: Small and lightweight, making it convenient to carry around and use while traveling.
  • Graphic Design: Includes a screen, keyboard, and touchpad integrated into one unit.
  • Desktop computer:
  • Size and weight: Larger and heavier, making it less convenient to move around.
  • Graphic Design: It consists of a central processing unit (tower), a separate monitor, a keyboard, and a mouse.

2. Power and performance:

  • Laptop:
  • the performance: Provides good performance for most daily uses, but may be less powerful compared to desktop computers intended for gaming or heavy tasks.
  • Cooling: Less efficient at cooling, which may affect performance when running heavy applications for long periods.
  • Desktop computer:
  • the performance: It is usually more powerful and customizable, making it suitable for games, graphic designs, and big data analysis.
  • Cooling: Has better cooling systems, allowing high-performance components to run without heat issues.

3. Update and upgrade:

  • Laptop:
  • Update: Limited ability to upgrade; Some components like RAM and storage can be upgraded, but the rest is mostly built-in and immutable.
  • Desktop computer:
  • Update: Easy to upgrade; Components such as the central processing unit (CPU), graphics card (GPU), memory (RAM), and storage can be changed or added.

4. Mobility and flexibility:

  • Laptop:
  • Mobility: Excellent for mobility, it can be used anywhere thanks to the built-in battery.
  • Flexibility: It can be easily used in public places or while traveling.
  • Desktop computer:
  • Mobility: Limited due to size and weight.
  • Flexibility: It needs a fixed place to work and cannot be moved easily.

5. Price:

  • Laptop:
  • Price: It is usually more expensive to get the same level of performance compared to desktop computers.
  • القيمة: You pay for mobility and comfort.
  • Desktop computer:
  • Price: Provides better value for performance, as more powerful components can be obtained at a lower price compared to laptops.
  • Economic:More economical when looking at raw performance.

6. Uses and needs:

  • Laptop:
  • Uses: Suitable for students, on-the-go professionals, and anyone who needs a device they can carry and use anywhere.
  • needs: Daily tasks, office work, surfing the Internet, and watching videos.
  • Desktop computer:
  • Uses: Suitable for gaming, graphic work, engineering design, programming, and any tasks that require high performance.
  • needsHeavy duty, intense use for long periods.

Choosing a laptop or desktop computer depends on your personal needs and daily uses. If you need a device that can be carried and used anywhere, a laptop may be the best choice. If you need high performance and the ability to upgrade, a desktop computer may be the most appropriate choice.

Computer prices in the market

Laptop prices:

  1. Apple MacBookAir M1:
    • Price: About $699.
    • Description: 13.3-inch Retina screen, M1 processor, 8 GB memory, 256 GB SSD storage.
  2. Dell XPS 15:
    • Price: About $1,099.
    • Description: 15.6-inch WUXGA screen, Intel Core i7-13700H processor, 16GB memory, 1TB SSD storage.
  3. Samsung Galaxy Book 4 Pro 360:
    • Price: About $1,499.
    • DescriptionIntegrated touch screen, powerful processor, 16 GB memory, 1 TB SSD storage.

Desktop computer prices:

  1. Dell XPS 8960:
    • Price: About $1,550.
    • Description: Intel Core i7 processor, RTX 4060Ti graphics card, 16GB memory, 512GB SSD storage.
  2. HP Envy Desktop:
    • Price: About $799.99.
    • Description: Intel Core i7 processor, 16 GB memory, 1 TB SSD storage.
  3. Apple Mac Mini (2023):
    • Price: About $499.
    • Description: M2 processor, 16 GB memory, 512 GB SSD storage.
Definition of computer