COMPUTER ORGANISATION | OPERATING SYSTEMS

ON THIS PAGE
SECTION 1 | OPERATING SYSTEMS
SECTION 2 | APPLICATION SOFTWARE
​SECTION 3 | FEATURES OF APPLICATIONS

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SECTION 1 | OPERATING SYSTEMS

An operating system (OS) is the software that manages the hardware and software resources of a computer. It acts as an intermediary between the computer hardware and the applications that run on the computer. The operating system provides the necessary support and services to run applications, manage memory, handle input/output operations, and perform other tasks. It is the first software that is loaded when the computer starts up, and it runs continuously in the background, providing the necessary resources and services to other programs. Examples of popular operating systems include Windows, macOS, Linux, and Android. The basic functions of an operating system include:

Managing files: An operating system is responsible for managing the file system, organizing files and directories, and providing access to files for both the user and the applications running on the computer.
Handling interrupts: The operating system is responsible for handling interrupts generated by hardware components, such as the keyboard or mouse, and ensuring that the computer responds in a timely manner.
Providing an interface: The operating system provides a user interface, such as a graphical user interface or command-line interface, allowing the user to interact with the computer and perform tasks.
Managing peripherals and drivers: The operating system manages peripheral devices, such as printers and storage devices, and provides drivers to allow the hardware to interact with the software. A graphical user interface (GUI) is a type of user interface that uses graphical elements, such as icons and windows, to allow the user to interact with the computer. A command-line interface (CLI) is a type of user interface that uses text-based commands to perform tasks and access information. A GUI is more user-friendly and easier to use than a CLI, but a CLI provides more control and is more efficient for advanced users.
Managing memory: The operating system manages the computer's memory, allocating memory to running applications and managing memory allocation and deallocation as needed. The operating system uses various algorithms, such as first-fit and best-fit, to determine how to allocate memory to running applications, and it also manages the freeing up of memory when applications are closed.
Managing multitasking: The operating system is responsible for managing multitasking, allowing multiple applications to run simultaneously and switching between them as needed.
Providing a platform for running applications: The operating system provides a platform for running applications, providing the underlying support and resources needed to run the software.
Providing system security: The operating system provides security features, such as user authentication, access control, and data encryption, to protect the computer and its data from unauthorized access and attack. The operating system also provides firewalls, antivirus software, and other security tools to prevent unauthorized access and protect against attacks.​
Managing user accounts: The operating system is responsible for managing user accounts, allowing multiple users to log in and use the computer and managing the permissions and access rights for each user.

SECTION 2 | APPLICATION SOFTWARE

Application software, also known as an app or application, is a type of computer software designed to perform specific tasks or functions for the user. Unlike system software, which manages and operates the computer system, application software is used directly by the user to accomplish a particular task, such as creating a document, managing data, or browsing the internet.​

Some examples of application software include:

• Word processors: Word processing software is used to create, edit, and format text documents. Examples of word processors include Microsoft Word, Google Docs, and Apple Pages.
• Spreadsheets: Spreadsheet software is used to organize and manipulate data in a tabular format. Examples of spreadsheet software include Microsoft Excel, Google Sheets, and Apple Numbers.
• Database management systems: Database software is used to store, organize, and manage large amounts of data. Examples of database software include Microsoft Access, Oracle, and MySQL.
• Email clients: Email software is used to send, receive, and manage email messages. Examples of email clients include Microsoft Outlook, Gmail, and Apple Mail.
• Web browsers: Web browsing software is used to access and view web pages on the internet. Examples of web browsers include Google Chrome, Mozilla Firefox, and Apple Safari.
• Computer-aided design (CAD) software: CAD software is used by designers and engineers to create detailed 2D and 3D models of products and buildings. Examples of CAD software include AutoCAD, SketchUp, and SolidWorks.
• Graphic processing software: Graphics software is used to create and manipulate visual images, such as photographs, illustrations, and logos. Examples of graphics software include Adobe Photoshop, GIMP, and CorelDRAW.

Application software is a vital component of modern computing, providing users with the tools and functionality they need to accomplish specific tasks and achieve their goals

SECTION 3 | COMMON FEATURES OF APPLICATIONS

Common features of applications include:

• Graphical User Interface (GUI): A graphical user interface is an interface that allows users to interact with the application using graphical elements such as windows, icons, buttons, and menus.
• Toolbars: Toolbars provide quick access to frequently used commands and functions.
• Menus: Menus provide a hierarchical list of commands and functions that can be accessed by the user.
• Dialogue Boxes: Dialogue boxes provide a way for the user to interact with the application by entering data, making selections, or responding to prompts.
• Help System: A help system provides assistance to the user, typically in the form of documentation, tutorials, or online help.

The importance of applications being intuitive to the user is crucial. Users should be able to easily understand the purpose and functions of the application without requiring extensive training or documentation. This can be achieved through the use of a well-designed graphical user interface (GUI), including features such as toolbars, menus, and dialogue boxes that are consistent and easy to navigate.

Toolbars provide quick access to frequently used functions and commands, which can save time and improve efficiency. Menus allow users to access a wider range of functions and commands, organized in a hierarchical manner, providing easy access to complex features.

Dialogue boxes provide a way for the user to interact with the application, for example, entering data, making selections, or responding to prompts. An effective dialogue box should be clear and easy to understand, with clear instructions and feedback.

A well-designed graphical user interface (GUI) is essential for ensuring that applications are intuitive to the user. By providing clear and consistent features such as toolbars, menus, and dialogue boxes, users can easily understand the application and its functions, improving their productivity and user experience.

1. What is an operating system and what is its role in a computer system?
2. What are the main functions of an operating system?
3. How does an operating system manage hardware and software resources in a computer?
4. How does an operating system handle multitasking and ensure that each application receives the necessary resources and services?
5. How does an operating system manage memory and allocate memory to running applications?
6. What is the difference between a graphical user interface and a command-line interface in an operating system?
7. How does an operating system provide security and protect the computer from unauthorized access and attack?
8. What are some common examples of operating systems, and how do they differ from each other in terms of features and functionality?

ALSO IN THIS TOPIC

COMPUTER ARCHITECTURE
SECONDARY MEMORY
OPERATING SYSTEMS
BINARY REPRESENTATION
LOGIC GATES
TOPIC 2 REVISION | NEW
KEY TERMINOLOGY
TOPIC 2 ANSWERS