What is the difference between total installs and active installs in the Android market?

Question

What is the difference between total installs and active installs?

I have 90 total installs for my app and only 47 active installs. What does it mean?

Answer 1

I don't know exactly about it. But, while observing one of my app statistics this was the observation:

Day 1 : 4 total user installs 1 active device installs

Day 3 : 4 total user installs 4 active device installs

According to the various discussion on web, active install may be related to total number of devices application is installed. But, there is something more to it, as pointed by john Active installs are how many instances of your app are on. So, even if the app is installed but not running it won't count!