What is "asynchronous" and "synchronous" in programming?

Pranam Bhat

- Please explain "asynchronous" and "synchronous" in programming in general with an example.

- What are the main benefits?

6 Replies

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Charles Andersen5y ago
asynchronous allows your program to continue without waiting for the operation to complete.
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Amit Kumar Singh5y ago
Hi,
- Synchronous basically means that you can only execute one thing at a time.
- Asynchronous means that you can execute multiple things at a time and you don't have to finish executing the current thing in order to move on to next one.
Regards,

Amit
+3
Sachin Singh5y ago
there are 3 things sync, async and parallel, sync means one after another, async means not parallel but without blocking the calling thread.

There is a huge misconception that async means parallel, we all know that javascript is based on a single thread model yet we can use async-await there so what does it mean javascript can really do things in parallel, no not at all, it just won't block the UI.

For example, suppose we are discussing a feature that uploads files. If you say its parallel i assume i can upload multiple files simultaneously. If you say its asynchronous i assume that i can upload one file and the UI thread is not blocked while it is uploading. The difference is subtle but significant.
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Rijwan Ansari5y ago
Hi,

This is all about sequencial or parallel execution.

Syncronous: Operations/executions happen one after another sequencially
Asyncronous: Operations/Executions runs in parallel and await whenever requried.

https://blog.trigent.com/synchronous-vs-asynchronous-request-handling/
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Rajanikant Hawaldar5y ago
Hello Pranam,

I recommend you to go through C#Corner Learn tutuorial, here its explained very well.

https://www.c-sharpcorner.com/learn/c-sharp-asynchronous-programming
+3
Satya Karki5y ago
Hi,

In simple term:

In synchronous operations tasks are performed one at a time and only when one is completed, the following is unblocked. In other words, you need to wait for a task to finish to move to the next one.

In asynchronous operations, on the other hand, you can move to another task before the previous one finishes. This way, with asynchronous programming you’re able to deal with multiple requests simultaneously, thus completing more tasks in a much shorter period of time.

You can understand from here. Synchronous operation runs one after another, however, async runs in parallel which reduces the overall execution time.

Check this link for more knowledge:
https://www.outsystems.com/blog/posts/asynchronous-vs-synchronous-programming/

Normal programiing is syncronous if you are not using async and await.
For async examples:
https://www.c-sharpcorner.com/article/async-and-await-in-c-sharp/
https://www.c-sharpcorner.com/UploadFile/84c85b/asynchronous-programming-with-C-Sharp-5-0/
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