This schema definition includes your API paths, the possible parameters they take, etc.

#### Data "schema"

The term "schema" might also refer to the shape of some data, like a JSON content.

In that case, it would mean the JSON attributes, and data types they have, etc.

#### OpenAPI and JSON Schema

* A particular program while it is **running** on the operating system.
    * This doesn't refer to the file, nor to the code, it refers **specifically** to the thing that is being **executed** and managed by the operating system.

* and in there, find the module `dependencies` (the file at `app/dependencies.py`)...
* and from it, import the function `get_token_header`.

That would refer to some package above `app/`, with its own file `__init__.py`, etc. But we don't have that. So, that would throw an error in our example. 🚨

    author_link: https://medium.com/@nilsdebruin
    link: https://medium.com/data-rebels/fastapi-how-to-add-basic-and-cookie-authentication-a45c85ef47d3
    title: FastAPI — How to add basic and cookie authentication
  - author: Nils de Bruin
    author_link: https://medium.com/@nilsdebruin
    link: https://medium.com/data-rebels/fastapi-google-as-an-external-authentication-provider-3a527672cf33

We will use this `Base` class we created before to create the SQLAlchemy models.

!!! tip
    SQLAlchemy uses the term "**model**" to refer to these classes and instances that interact with the database.

    But Pydantic also uses the term "**model**" to refer to something different, the data validation, conversion, and documentation classes and instances.

Import `Base` from `database` (the file `database.py` from above).