Class notes Operating Systems Notes

COMPUTER STUDIES TOPIC: Operating Systems OBJECTIVES: 1. Definition, Role, Structure, Resources and Functions of an Operating system. 2. Types of Operating Systems 3. How an Operating System Organizes Information. 4. Managing Files and Folders Using Windows OS. 5. Managing Storage Devices Using Windows OS. 6. Installation and Configuration of an Operating System. Definition An operating system (OS) is a set of programs that manage the basic operations of the computer system. These programs are loaded into the main memory when the computer is turned on and remain there until the computer is turned off. Role/Importance of an Operating System The OS acts as an interface between the user and the computer, handling matters such as running and storing programs and storing and processing data. The OS allows users to concentrate on their own tasks or applications rather than on the complexities of managing the computer. Structure of an Operating System. An Operating system has several layers. The lowest layer is the hardware and the highest being the user application. The kernel is the core of an Operating System. It manages the communication between hardware and software resources. The outer part of an OS that the user sees, is the Shell or User Interface USER APPLICATION USER APPLICATION USER APPLICATION USER APPLICATION User interface APPLICATION PROGRAMMING INTERFACE / API EXTENSION Kernel Space File System / Memory Management / Process Management / I.O. Management / Device Management. DEVICE DRIVERS HARDWARE