How google analytics show sessions without users?

Question

I set up google analytics campaign tracking in my android app.

I don't understand How google shows me that there is one session with zero new users. as you could see in the bellow picture:

if there is no new users , how it's possible to have session ?

Answer 1

According to the analytics blog new users are defined as:

New users : beyond installs, new users shows you how many active users actually launch your application after it's installed. This is a key metric to see even beyond installs, reported from the Google Analytics Services SDK. Tracing the path up the funnel shows you clearly which sources don't just account for those installing your app, but which lead to passionate users who spend time with your app leading to in-app conversions

This seems to indicate that the user you see in your report are actually returning users who had previously installed the app