What is multitasking and how does the OS manage it?

Multitasking is the concurrent execution of multiple tasks, managed by the operating system through process scheduling.

In more detail, multitasking is a fundamental aspect of modern operating systems, allowing multiple tasks, also known as processes, to run simultaneously on a single computer. This doesn't necessarily mean that each task is actually running at the exact same moment. Instead, the operating system rapidly switches between tasks, giving the illusion that they're running concurrently.

The operating system manages multitasking through a mechanism known as process scheduling. This involves deciding which tasks should run, when they should run, and for how long. The goal is to maximise the use of the processor and ensure that all tasks get their fair share of computing resources. There are various scheduling algorithms that the operating system can use, such as First-Come, First-Served (FCFS), Shortest Job Next (SJN), and Round Robin (RR), each with their own advantages and disadvantages.

In addition to process scheduling, the operating system also has to manage the resources that each task needs. This includes memory, input and output devices, and any data that the task might need. The operating system uses a variety of techniques to manage these resources, such as virtual memory and device drivers.

Multitasking also involves the concept of context switching. This is the process of saving the state of a task, so that it can be resumed later. This is necessary because the operating system needs to switch between tasks rapidly. When a task is switched out, its state is saved to memory. When it's switched back in, its state is loaded back into the processor. This allows the task to continue from where it left off.

In conclusion, multitasking is a complex process that involves careful management of tasks and resources by the operating system. It's a crucial aspect of modern computing, allowing us to run multiple applications at the same time and make the most of our computer's resources.