Но внутреннее устройство **конкурентности** и **параллелизма** довольно разное.

Чтобы это понять, представьте такую картину:

### Конкурентные бургеры

<!-- The gender neutral cook emoji "🧑‍🍳" does not render well in browsers. In the meantime, I'm using a mix of male "👨‍🍳" and female "👩‍🍳" cooks. -->

            - raw_headers
            - render
            - init_headers
            - headers
            - set_cookie
            - delete_cookie

::: fastapi.responses.ORJSONResponse
    options:
        members:
            - charset
            - status_code
            - media_type
            - body
            - background
            - raw_headers
            - render
            - init_headers

* Import `Jinja2Templates`.
* Create a `templates` object that you can re-use later.
* Declare a `Request` parameter in the *path operation* that will return a template.
* Use the `templates` you created to render and return a `TemplateResponse`, pass the name of the template, the request object, and a "context" dictionary with key-value pairs to be used inside of the Jinja2 template.

```Python hl_lines="4  11  15-18"

## importe `Header`

Primeiro importe `Header`:

=== "Python 3.10+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/header_params/tutorial001_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001.py!}
    ```

## Declare parâmetros de `Header`

# Header Parameters

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header`

First import `Header`:

=== "Python 3.10+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

<style>
.md-content .md-typeset h1 { display: none; }
</style>

<p align="center">
  <a href="https://fastapi.tiangolo.com"><img src="https://fastapi.tiangolo.com/img/logo-margin/logo-teal.png" alt="FastAPI"></a>
</p>
<p align="center">
    FastAPI Framework, hochperformant, leicht zu erlernen, schnell zu programmieren, einsatzbereit
</p>
<p align="center">

                </mxCell>
                <mxCell id="32" value="" style="pointerEvents=1;shadow=0;dashed=0;html=1;fillColor=#505050;labelPosition=center;verticalLabelPosition=bottom;verticalAlign=top;outlineConnect=0;align=center;shape=mxgraph.office.devices.laptop;strokeColor=none;" parent="33" vertex="1">
                    <mxGeometry width="500" height="350" as="geometry"/>
                </mxCell>

        return False
    dunder_call = getattr(call, "__call__", None)  # noqa: B004
    return inspect.iscoroutinefunction(dunder_call)


def is_async_gen_callable(call: Callable[..., Any]) -> bool:
    if inspect.isasyncgenfunction(call):
        return True
    dunder_call = getattr(call, "__call__", None)  # noqa: B004
    return inspect.isasyncgenfunction(dunder_call)

                </mxCell>
                <mxCell id="32" value="" style="pointerEvents=1;shadow=0;dashed=0;html=1;fillColor=#505050;labelPosition=center;verticalLabelPosition=bottom;verticalAlign=top;outlineConnect=0;align=center;shape=mxgraph.office.devices.laptop;strokeColor=none;" parent="33" vertex="1">
                    <mxGeometry width="500" height="350" as="geometry"/>
                </mxCell>

                </mxCell>
                <mxCell id="3" value="&lt;font face=&quot;Roboto&quot;&gt;&lt;span style=&quot;font-size: 24px&quot;&gt;Server&lt;/span&gt;&lt;/font&gt;" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;strokeWidth=3;fontFamily=Roboto Mono, mono;FType=g;" parent="1" vertex="1">
                    <mxGeometry x="755" y="290" width="300" height="80" as="geometry"/>
                </mxCell>