My interpretation of AsyncTask

AsyncTask has three generic type

	Params, the type of the parameters sent to the task upon execution.
	Progress, the type of the progress units published during the background computation.
	Result, the type of the result of the background computation

?
1
2	Private class ShowDialogAsyncTask extends
        AsyncTask<Params, Progress, Result>{....}


AsyncTask goes through 4 steps 


	onPreExecute(),invoked on the UI thread immediately after the task is executed.
	 doInBackground(Paaram ...),invoked on the background thread immediately after onPreExecute()finishes executing.
	onProgressUpdate(Progress...) invoked on the UI thread after a call to publishProgress(Progress...).
	 onPostExecute(Result), invoked on the UI thread after the background computation finishes. 


Source here: http://www.javasrilankansupport.com/2012/11/asynctask-android-example-asynctask-in.html