Is there any difference between Activityname.this() & this?

Is there any difference between Activityname.this() & this?

Is there any difference between Activityname.this() & this in Android ? I
am trying to open an activity from same activity with button in dialog box
? I am using getApplicationContext() in intent. In some mobiles it
works.But in other it gives force close ? What should i use & why ?