What is an asynchronous controller in ASP.NET MVC?

What is an asynchronous controller in ASP.NET MVC?

-AsyncController is a class which is used to create asynchronous action methods which we use for lengthy processes.

-By using asynchronous controller we can optimize the performance of web server by avoiding the usage of extra resources once a request is processed.

-The AsyncController class is more useful for the calls of web service which takes long time to process.