If you have Flash Payer installed on your Mac, you were probably asked these last few days to update to version 11.3.300.257. It fixes some more bugs and plugs some more security breaches but most importantly, it brings one more feature to the software, the ability to update itself without having to ask the user. You might have noticed that the last window displayed during the update looked different from previous updates.
It is at that moment that you decide of the course followed by Flash Player. The default setting is that it will update by itself automatically. You can also ask to keep the previous system with an update alert or keep the software from performing any update or even looking for one, but as shown on this screenshot, it is not recommended
By Machmeter, original by Lionel