How does it work, the naming convention for Django INSTALLED_APPS?

The tutorial on the site creates an app named polls. It's using django 1.9, so in the INSTALLED_APPS it is:

polls.apps.PollsConfig

I'm watching a tutorial he names the app newsletter and in INSTALLED_APPS he has

newsletter

he's using 1.8, though. I am using 1.9. I've watched other tutorials and they also just add a name without dots in the syntax as he does. I realize things may be different, that's understood. To be clear if I named my app dogs,. in the installed apps it would be named like this

dogs.apps.DogsConfig

or if it was tree it would be

tree.apps.TreeConfig

Is that how the naming convention goes? also I would assume things would get shorter in newer versions and more convenient. so to go from just adding

newsletter,

to having to type out

polls.apps.PollsConfig

seems weird to me. But I'm new so I maybe missing something. Any and all advice is welcome