<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`

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

* 📝 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).

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>.

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).

    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*").

When you pass the file to `fastapi run` it will detect automatically that it is a single file and not part of a package and will know how to import it and serve your FastAPI app. 😎

## Deployment Concepts

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