Operating Systems Notes

Operating Systems

  • An operating system (OS) is a set of programs that coordinate all the activities among computer or mobile device hardware.

Operating System Functions

  • Starting Computers and Mobile Devices
    • If a computer or mobile device is off, pressing the power button will turn it on.
  • Power Options: Operating systems include various power options.
    • Sleep mode: Saves any open documents, running programs, or apps to RAM, turns off all unneeded functions, and places the computer in a low-power state.
    • Hibernate mode: Saves any open documents and running programs or apps to an internal hard drive before removing power from the computer or device.
  • User Interface (UI):
    • Controls how you enter data and instructions and how information is displayed on the screen.
    • Graphical User Interface (GUI): Allows interaction with menus and visual images.
    • Command-Line Interface: User types commands represented by short keywords or abbreviations, or presses special keys to enter data and instructions.
  • Program Management: How an operating system handles programs directly affects productivity.
    • Single tasking: Allows only one program to run at a time.
    • Multitasking: Allows multiple programs to run simultaneously.
    • Foreground: The program currently being used.
    • Background: Other programs that are running but not actively in use.
    • Single user: One user can use the system at a time.
    • Multiuser: Multiple users can access the system concurrently.
  • Memory management: Optimizes the use of the computer or device’s internal memory.
    • Virtual memory: A portion of a storage medium functioning as additional RAM.
  • The operating system determines the order in which tasks are processed.
  • Drivers:
    • A driver is a small program that tells the operating system how to communicate with a specific device.
    • Plug and Play: Automatically configures new devices as you install or connect them.
  • Performance Monitor: A program that assesses and reports information about various computer resources and devices.
  • Operating systems typically provide a means to establish Internet connections.
  • Many programs, including operating systems, include an automatic update feature that regularly provides new features or corrections to the program.
  • Operating systems often provide users with a variety of tools related to managing a computer, its devices, or its programs.
    • File Manager
    • Search
    • Image Viewer
    • Uninstaller
    • Disk Cleanup
    • Disk Defragmenter
    • Screen Saver
    • File Compression
    • PC Maintenance
    • Backup and Restore
  • Some operating systems are designed to work with a server on a network.
    • These multiuser operating systems allow multiple users to share a printer, Internet access, files, and programs.
  • A network administrator uses the server operating system to:
    • Add and remove users, computers, and other devices.
    • Configure the network, install software, and administer network security.
  • User Accounts:
    • A user account enables a user to sign in to, or access resources on, a network or computer.
      • A user name, or user ID, identifies a specific user.
      • A password is a private combination of characters associated with the user name.

Types of Operating Systems

  • Desktop Operating Systems
  • Server Operating Systems
  • Mobile Operating Systems

Desktop Operating Systems

  • A desktop operating system is a complete operating system that works on desktops, laptops, and some tablets.
    • Windows
    • Mac OS
    • UNIX
    • Linux
    • Chrome OS
  • Windows
    • The latest versions of Windows offer these features:
      • Uses tiles to access apps.
      • Includes the desktop interface.
      • Support for input via touch, mouse, and keyboard.
      • Email app, calendar app, and browser included.
      • Photos, files, and settings you can sync with OneDrive.
      • Enhanced security through an antivirus program, firewall, and automatic updates.
      • Windows Store offers additional applications for purchase.
  • Macintosh OS
    • The Macintosh operating system has earned a reputation for its ease of use.
    • Latest version is OS X.
  • UNIX
    • UNIX is a multitasking operating system developed in the early 1970s.
  • Linux
    • Linux is a popular, multitasking UNIX-based operating system.
  • Chrome OS
    • Chrome OS is a Linux-based operating system designed to work primarily with web apps.

Server Operating Systems

  • Server operating system is a multiuser operating system that organizes and coordinates how multiple users access and share resources on a network.
    • Windows Server
    • OS X Server
    • UNIX
    • Linux

Mobile Operating Systems

  • The operating system on mobile devices and many consumer electronics is called a mobile operating system and resides on firmware.
    • Android
    • iOS
    • Windows Phone
  • Android
    • Android is an open source, Linux-based mobile operating system designed by Google for smartphones and tablets.
  • iOS
    • iOS, developed by Apple, is a proprietary mobile operating system specifically made for Apple’s mobile devices.
  • Windows Phone
    • Windows Phone, developed by Microsoft, is a proprietary mobile operating system that runs on some smartphones.