* For HTTPS, **the server** needs to **have "certificates"** generated by a **third party**.
    * Those certificates are actually **acquired** from the third party, not "generated".
* Certificates have a **lifetime**.
    * They **expire**.
    * And then they need to be **renewed**, **acquired again** from the third party.
* The encryption of the connection happens at the **TCP level**.
    * That's one layer **below HTTP**.

It gives you all the flexibility to choose the ones that fit your project the best.

And you can use directly many well maintained and widely used packages like `passlib` and `python-jose`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

But it provides you the tools to simplify the process as much as possible without compromising flexibility, robustness, or security.

    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md){.internal-link target=_blank}.

!!! tip
    Having `dependencies` in the `APIRouter` can be used, for example, to require authentication for a whole group of *path operations*. Even if the dependencies are not added individually to each one of them.

!!! check

---

Common examples of CPU bound operations are things that require complex math processing.

For example:

* **Audio** or **image processing**.

In this case, it requires the scope `me` (it could require more than one scope).

!!! note
    You don't necessarily need to add different scopes in different places.

    We are doing it here to demonstrate how **FastAPI** handles scopes declared at different levels.

**FastAPI** doesn't require you to use a SQL (relational) database.

But you can use any relational database that you want.

Here we'll see an example using <a href="https://www.sqlalchemy.org/" class="external-link" target="_blank">SQLAlchemy</a>.

    {!> ../../../docs_src/settings/app02/main.py!}
    ```

!!! tip
    We'll discuss the `@lru_cache` in a bit.

    For now you can assume `get_settings()` is a normal function.

And then we can require it from the *path operation function* as a dependency and use it anywhere we need it.

=== "Python 3.9+"

    ```Python hl_lines="17  19-21"
    {!> ../../../docs_src/settings/app02_an_py39/main.py!}
    ```