Q) What are models?

Models are the definition of the data schema that will be handled by Vuex ORM.

How to define a model?

Create a class that extend Vuex ORM Model.

Where is the official documentation?

https://vuex-orm.org/guide/model/defining-models.html

Q) What is this file structure based on?

https://github.com/vuex-orm/vuex-orm-examples-nuxt/tree/master/models