Models
A model is a concept that is part of Model-View-Controller, the models represent a structure that contains, manages, formats, and wraps the data, usually, it is related to the concept of an Object–relational mapping , an Active record, and an Object Data Modelling (it is similar to an Object–relational mapping but for NoSQL databases), in summary, way you will save and fetch the content using models.
Writing models
Read this.
Field types
Read this.
Migrations
Read this.
Making queries
Read this.
Where are the models?
It where in breathecode/APP_NAME/models.py
.