IS102 Module 2

• Operating systems


  • Manage hardware devices on a system (both internal and external)
  • Provide user interface
  • Provide storage management
  • Provide process and service management
  • Provide memory and I/O management
  • Provide security and resource protection
• Kernel


  The heart of the OS and runs with the highest priority
• Categories of operating systems

  • Single-tasking versus multitasking
  • Single-user versus multiuser
  • General-purpose versus real-time
• Single-tasking operating system


  Can execute only a single process at a time
• Multitasking operating system


  Quickly switches between all the processes that are loaded into memory and scheduled to run
• Single-user operating system


  Allows only one user at a time to interact with the OS user interface, start processes, make system configuration changes, and interact directly with the file system
• Multiuser operating system


  Allows multiple users to sign in to it, start and stop processes, interact with the user interface, and access the local file system
• General-purpose operating system


  Designed to provide a convenient user interface and run applications in a home or business environment with reasonable performance
• Real-time operating system (RTOS)


  Designed to process inputs and produce outputs in a very specific and repeatable amount of time
• Operating system roles

  • Client
  • Server
  • Standalone
• Client operating system


  Primary purpose is to run applications requested by a user and request data from network servers as necessary
• Server operating system

  Primary purpose is to share network resources and provide network services to clients
• Standalone operating system


  Not designed to interact with other OSs or access network resources
• Primary operating system components

  • Boot procedure
  • Process and service management
  • Memory and I/O management
  • Security and resource protection
  • Kernel
• All computers perform three basic tasks: input, processing, and output
• An operating system (OS) provides the foundation upon which to run the components of a computer and execute applications
• A basic task of an OS is to enable a computer to perform I/O functions so that it can use software applications and communicate with computer hardware
• Early OSs tended to be single-tasking, but modern systems are largely multitasking
• A true multiuser system is one in which multiple users access and run a single application on a single computer at the same time
• The BIOS is a low-level program code that operates between the computer hardware and a higher-level operating system to initiate communication with hardware devices
• Device drivers can extend the native function of an operating system to provide access and control over different types of devices
• The history of operating systems and computers represents a progression from huge computers to large computers to desktop-sized computers that have powerful operating systems
• One of the most significant advances in operating systems is the refinement of the GUI in Windows-based and Mac OS systems
• Current popular OSs include Windows 10, Server 2012/R2, Server 2016, Server 2019, UNIX/Linux, and macOS Mojave