Operating System PDF

Operating System Lecture 2 – Part (2) By Assist Prof. Dr. Waleed AL-Hashimi Objectives This lecture provides an overview of the operating system (OS), its fundamental functions, and its importance in managing a computer’s hardw...

Operating System Lecture 2 – Part (2) By Assist Prof. Dr. Waleed AL-Hashimi Objectives This lecture provides an overview of the operating system (OS), its fundamental functions, and its importance in managing a computer’s hardware and software resources. It aims to equip students with an understanding of how the OS allocates resources, manages processes, organizes memory, and enables user interaction through graphical and command-line interfaces. Operating System ❑ An operating system is a software program that controls and manages the hardware and software resources of a computer. It provides essential services to both the user and applications. Importance of OS in Managing Hardware and Software Resources 1. Resource Management: The OS allocates resources such as CPU time, memory space, storage, and input/output devices to different applications and users. 2. Process Management: The OS controls the execution of programs by managing processes. It handles process creation, scheduling, and termination, ensuring that multiple programs can run smoothly without interference. 3. Memory Management: The OS manages the computer's memory (RAM), allocating space for programs and freeing it up when no longer needed. 4. File System Management: The OS organizes and manages data storage through a file system, which allows users to save, retrieve, and organize files on their computer. 5. Device Management: The OS manages communication between the computer and peripheral devices like printers, scanners, and external drives. 6. User Interface (UI): The OS provides a user interface (GUI or CLI) that allows users to interact with the system. It simplifies tasks like launching programs, organizing files, and configuring settings. The User Interface (UI) When it comes to interacting with a computer, there are two primary types of user interfaces that users encounter: the Graphical User Interface (GUI) and the Command Line Interface (CLI). Each offers a different way to control and manage a computer's functions. Graphical User Interface (GUI) : A Graphical User Interface (GUI) is a visual-based interface that allows users to interact with the computer through graphical elements such as icons, windows, and menus. Command Line Interface (CLI): A Command Line Interface (CLI) is a text-based interface where users interact with the computer by typing commands. Instead of clicking on icons or navigating through menus, users input specific text commands to perform tasks. Use of Common Icons and the Status Bar ❑ File and Folder Icons File and folder icons represent documents, images, music files, and directories on your laptop. They look different from application icons and typically have a folder shape (for directories) or a document shape (for individual files). ❑ Application Icons Application icons are shortcuts to programs installed on your computer. They often display the logo or symbol of the application, helping you recognize them quickly. ❑ System Icons System icons provide access to key settings, like Wi-Fi, volume, and battery status. They are usually found on the status bar or taskbar. Menu and Menu Selection ❑ Menus provide a structured way to access features and tools in an application, helping you navigate and perform tasks efficiently. ❑ Types of Menus ▪ Main Menu: Typically found at the top of applications (e.g., File, and View), providing overall control and major functions. ▪ Drop-Down Menus: Accessible by clicking on main menu items, showing a list of related actions. ▪ Pop-up Menu (Context Menu): These menus appear when you right-click on an object or element. They offer contextually relevant options for that specific item ❑ Using Menus Common Options Examples: File: Open, save, or close files. Edit: Cut, copy, paste, and undo actions. View: Change layout or zoom ❑Menu Selection: Menu selection refers to the process of interacting with a menu to choose a specific option. ❑Interaction Methods: Clicking: Using a mouse or touchpad to select an option. Touch: On touchscreen devices. Keyboard Shortcuts: Using keys like "Alt" + a letter or arrow keys to navigate and select. Gestures: Swiping or tapping patterns in mobile interfaces. ❑ Menu Selection in Software and Devices ❑ In software, menu selection enables: Navigation between different features or settings. Execution of commands like “Save,” “Copy,” or “Print”. Configuration of preferences. In hardware devices like microwaves or washing machines, menus guide users through operational settings. Concept of Folders and Directories What are Folders and Directories? Folders are virtual containers that organize files. Directories is another term often used for folders. Path Navigation Explanation: A file path shows the location of a file within the folder hierarchy, such as C:\Documents\Photos\ZMC.jpg Opening and Closing Windows ❑ Opening Windows Applications and files can be accessed via the Start menu (Windows) or Finder (macOS). ❑ Managing Open Windows Minimize, Maximize, and Close: Minimize: Hide the window in the taskbar. Maximize: Make the window fill the screen. Close: Exit the application or file. Resizing and Moving Windows Drag window edges to resize. Click and drag the title bar to move the window around. Creating Shortcuts ❑ Shortcuts are quick links to files or applications, helping you access frequently used items without searching. ❑ How to Create a Shortcut Windows: Right-click the item, select "Create Shortcut.“ macOS: Drag the item while holding Option and Command to create an alias. Benefits of Using Shortcuts Quick access to commonly used files or applications. Organize frequently used shortcuts on the desktop or taskbar. Summary ▪ Resource Management: Allocates CPU, memory, and devices to applications. ▪ Process Handling: Manages program execution for smooth multitasking. ▪ Memory & File Control: Organizes memory use and file storage. ▪ User Interface: Provides GUI and CLI for user interaction. ▪ Shortcuts & Menus: Simplifies access to files and applications. End-of-session questions 1. What is the role of an operating system in resource management? 2. Explain how an operating system manages processes and ensures smooth execution of multiple programs. 3. Describe the difference between GUI and CLI. Which do you think is more user friendly and why? 4. How does the operating system manage memory, and why is this important? 5. Discuss the benefits of creating shortcuts for frequently used files or applications. Textbook ▪ Modern Operating Systems" by Andrew S. Tanenbaum and Herbert Bos