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Purposes of an Operating System (OS)
The operating system is the master program that manages all of the computer's hardware and software. It acts as the essential intermediary, allowing you and your applications to interact with the complex electronics inside.
Need to know
What you need to know
- **Processor (CPU) Management:** The OS decides which process gets to use the CPU and for how long. It uses scheduling algorithms to allocate CPU time, allowing for multitasking where multiple programs appear to run at once.
- **Memory Management:** The OS allocates blocks of main memory (RAM) to programs and data. It ensures that one program cannot access or corrupt the memory space of another. It also provides **virtual memory**, using secondary storage to extend RAM when needed.
- **I/O Device Management:** The OS communicates with input/output devices (like keyboards, printers, and network cards) through software called **device drivers**. It manages data transfer to and from these devices, often using interrupts to signal completion or errors.
- **Secondary Storage Management:** The OS manages all secondary storage devices (HDDs, SSDs). It is responsible for file systems, which track where files are physically stored, available space, and access permissions.
Explanation
The Computer's Conductor
- A user issues a command, such as clicking an application icon to open it.
- The OS locates the application on secondary storage, allocates a portion of RAM, and loads the program's instructions into it.
- The OS manages the hardware on behalf of the application, handling screen output, keyboard input, and network requests via device drivers.
- The OS scheduler allocates CPU time to the new application process, managing it alongside all other running processes to ensure the system remains responsive.