What is the significance of after() in this code?

[W. eWatson]

Martin P. Hellwig wrote:
> W. eWatson wrote:
>> See Subject.
>>     def StackImages(self):
>>         self.Upload("P")
>>         self.after_id = self.master.after(10000,self.GetFrameOne)
> 
> If you are talking tkinter here, it is an alarm callback.
> See http://effbot.org/tkinterbook/widget.htm
> 
Very good. I recall encountering this once before. I knew it had to be 
something like that, since the code does not provide a method called 
after().