- AutoPostback or Postback is nothing but submitting page to server.
- AutoPostback is webpage going to server, Server processes the values and sends back to same page or redirects to different page.
Click on the above button and observe the progressbar of browser.
Just Postback happened
When you click on above button, the request goes to server below. The server processes the request(The code executes) and returns the output(response) to webpage.
In the above picture , you can observe what happens on server side. Page.IsPostback value will be true if it is postback.