Difference between Concurrency and Parallelism in Operating System

Concurrency and parallelism are related but not the same terms, and they are sometimes confused. The key distinction between concurrency and parallelism is that concurrency is concerned with dealing with several things simultaneously or managing concurrent events while essentially hiding latency. In contrast, parallelism is about doing multiple tasks simultaneously that help to increase the system speed.

In this article, you will learn about the difference between Concurrency and Parallelism in the operating system. But before discussing the differences, you must know about Concurrency and Parallelism in the operating system.

What is Concurrency?

Concurrency refers to an application that performs multiple tasks simultaneously. It is a technique for reducing system response time by utilizing a single processing unit. It creates the illusion of parallelism. However, the chunks of a task aren't parallel processed. Still, inside the application, over one task is being executed simultaneously, and it doesn't complete one work before beginning the next. It is achieved via the interleaving operation of processes on the processor or by context switching. It enhances the amount of work that can be completed at a time.

Concurrency allows multi-party access to shared resources and needs some type of communication. It performs on a thread until it makes any helpful progress, then it stops the thread and switches to another thread until it makes any useful progress again.

What is Parallelism?

Parallelism refers to an application in which tasks are separated into smaller sub-tasks that are processed concurrently or parallel. It boosts the system's throughput and computing performance by utilizing numerous processors and allows single sequential CPUs to do many things "seemingly" simultaneously.

Parallelism causes CPU and I/O activity in one process to overlap with CPU and I/O activities in another process. However, when concurrency is applied, it increases speed by overlapping the I/O operations of one process with the processor process of another process.

Main differences between Concurrency and Parallelism in Operating System

Here, you will learn the main differences between concurrency and parallelism in the operating system. The operating system has various differences between the concurrency and parallelisms in the operating system are as follows:

1. Concurrency is the task of simultaneously running and managing numerous computations. On the other hand, parallelism is the task of executing numerous computations at the same time.
2. The non-deterministic control flow approach is called concurrency. On the other hand, parallelism is a deterministic control flow technique.
3. Concurrency is achieved via the interleaving of processes on the CPU or, in other words, by context switching. On the other hand, parallelism is achieved by the use of several CPUs.
4. A single processing unit may be utilized to implement concurrency. On the other hand, parallelism may not be achieved with a single processing unit. It necessitates the use of numerous processing units.
5. Concurrency deals with many things simultaneously. On the other hand, parallelism does a lot of things simultaneously.
6. Debugging is very complex in concurrency. On the other hand, Debugging is also complex in parallelism but simpler than concurrency.

Head-to-head comparison between Concurrency and Parallelism

Here, you will learn the head-to-head comparison between Concurrency and Parallelism in the operating system. The operating system has various differences between Concurrency and Parallelism as follows:

Conclusion

In summary, concurrency and parallelism are not the same things. Concurrency may involve the various tasks executing and having overlapping time. In contrast, parallelism involves multiple tasks executing concurrently with the same start and finish time.