<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path`

And then, there would be another program (in some cases it's another program, in some cases it could be the same TLS Termination Proxy) that would talk to Let's Encrypt, and renew the certificate(s).

<img src="/img/deployment/https/https.svg">

The **TLS certificates** are **associated with a domain name**, not with an IP address.

I'll show you some concrete examples in the next chapters.

---

Then the next concepts to consider are all about the program running your actual API (e.g. Uvicorn).

## Program and Process

We will talk a lot about the running "**process**", so it's useful to have clarity about what it means, and what's the difference with the word "**program**".

### What is a Program

    The **FastAPI** specific code is as small as always.

## ORMs

**FastAPI** works with any database and any style of library to talk to the database.

A common pattern is to use an "ORM": an "object-relational mapping" library.

An ORM has tools to convert ("*map*") between *objects* in code and database tables ("*relations*").

* 📝 Reword in docs, from "have in mind" to "keep in mind". PR [#10376](https://github.com/tiangolo/fastapi/pull/10376) by [@malicious](https://github.com/malicious).
* 📝 Add External Link: Talk by Jeny Sadadia. PR [#10265](https://github.com/tiangolo/fastapi/pull/10265) by [@JenySadadia](https://github.com/JenySadadia).

Then adjust the Uvicorn command to use the new module `main` instead of `app.main` to import the FastAPI object `app`.

## Deployment Concepts

Let's talk again about some of the same [Deployment Concepts](concepts.md){.internal-link target=_blank} in terms of containers.

Vielleicht möchten Sie ihre Kurse ausprobieren:

* <a href="https://training.talkpython.fm/fastapi-courses" class="external-link" target="_blank">Talk Python Training</a>

You might want to try their courses:

* <a href="https://training.talkpython.fm/fastapi-courses" class="external-link" target="_blank">Talk Python Training</a>

The cashier gives you the number of your turn.

<img src="/img/async/concurrent-burgers/concurrent-burgers-04.png" class="illustration">

While you are waiting, you go with your crush and pick a table, you sit and talk with your crush for a long time (as your burgers are very fancy and take some time to prepare).

On the other side, there are thousands of users in the chat systems, so there's a high chance you'll find someone to talk to there, almost all the time. 😄

## Sponsor the author

You can also financially support the author (me) through <a href="https://github.com/sponsors/tiangolo" class="external-link" target="_blank">GitHub sponsors</a>.