Outline the purpose of an operating system (OS). Explain the interaction that takes place between an OS, applications, and computer hardware.
The purpose of an operating system (OS) is to provide a software interface between the computer hardware and user applications. It manages computer resources and facilitates their efficient utilization. Some key purposes of an OS are:
1. Resource Management: The OS allocates and manages system resources such as CPU, memory, disk space, and peripherals. It ensures that multiple applications can run concurrently and share resources without conflict.
2. Process Management: The OS manages processes, which are executing instances of a program. It schedules processes, assigns CPU time, and allows them to execute in an orderly manner. It deals with process synchronization and communication.
3. Memory Management: The OS handles memory allocation and deallocation for running applications. It ensures efficient memory utilization by allowing multiple applications to share memory and managing virtual memory techniques like paging and swapping.
4. File System Management: The OS manages files and directories on storage devices. It provides file organizations, access control, and ensures data integrity and reliability.
5. User Interface: The OS provides a user-friendly interface for users to interact with the computer system. It allows users to execute commands, run applications, and access system resources through graphical or command-line interfaces.
Interaction between an OS, applications, and computer hardware:
1. Application Interface: The OS provides a set of application programming interfaces (APIs) that applications can use to access system resources. These APIs act as a bridge between the application software and the underlying hardware. Applications interact with the OS by making system calls, which trigger specific OS services.
2. Hardware Abstraction: The OS abstracts the underlying hardware, providing a uniform interface for applications. It shields applications from the hardware complexity by providing a standardized set of services, regardless of the specific hardware configuration.
3. System Calls: Applications interact with the OS through system calls. These calls request specific services from the OS, such as opening a file, allocating memory, or performing input/output operations. The OS interprets these requests and provides the necessary services by interacting with the hardware.
4. Hardware Management: The OS manages hardware resources on behalf of applications. It controls the CPU by scheduling processes, allocating memory to applications, managing the disk storage system, handling input/output devices, and maintaining network connectivity.
5. Application Execution: The OS provides an execution environment for applications. It loads the application code into memory, sets up the necessary data structures, and manages the execution process. The OS ensures fairness, security, and protection of applications by enforcing access control policies and resource isolation.
Overall, the OS acts as an intermediary between applications and hardware, managing and coordinating their interactions to provide a stable and efficient computing environment.