What are Action Methods in ASP.NET MVC?

Action Methods are methods defined in the controller class and are responsible to perform operations based on the user's inputs like entering a URL into the browser, clicking a link, and submitting a form.

http://www.codeproject.com/Articles/595024/Controllers-and-Actions-in-ASP-NET-MVC

http://msdn.microsoft.com/en-us/library/dd410269(v=vs.100).aspx