How is this "json" folder in the "www" directory generated?

Hello! I’m new to Ionic and I’ve been taking at look at example projects the past few days. I’m already familiar with the project structure, and I know that the “www” directory includes everything that has been compiled. However, I have a small question:

I found a project in which there’s several .json files in the “myproject/www/assets/json” directory, like this:


But I’m not quite sure how this is generated. My first guess is that this is, in some way, the project’s “compiled” database. I noticed it uses Firebase (with AngularFire), and my first thought is that these json files were generated from the json tree in the Firebase database. However, I’m not too sure and I’d really appreciate if someone could shed a little bit of light on this.

Thank you in advance, and I wish you all a great weekend.