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. -->

```

Read the new docs: [Query Parameter Models](https://fastapi.tiangolo.com/tutorial/query-param-models/).

#### `Header` Parameter Models

Use Pydantic models for `Header` parameters:

```python
from typing import Annotated

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool

# Header Parameter Models { #header-parameter-models }

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

Podrías querer probar sus servicios y seguir sus guías:

You might want to try their services and follow their guides:

* <a href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" class="external-link" target="_blank">Render</a>

    <div class="item">
      <a title="Deploy & scale any full-stack web app on Render. Focus on building apps, not infra." style="display: block; position: relative;" href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" target="_blank">
        <span class="sponsor-badge">sponsor</span>
        <img class="sponsor-image" src="/img/sponsors/render-banner.svg" />
      </a>
    </div>
    <div class="item">

Bạn có thể thử các dịch vụ của họ và làm theo hướng dẫn của họ:

* Import `Jinja2Templates`.
* Create a `templates` object that you can reuse 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.

{* ../../docs_src/templates/tutorial001.py hl[4,11,15:18] *}

     */
    int DCERPC_LAST_FRAG = 0x02; /* Last fragment */
    /**
     * Pending cancel flag - indicates cancel was pending at sender
     */
    int DCERPC_PENDING_CANCEL = 0x04; /* Cancel was pending at sender */
    /**
     * Reserved flag for future use
     */
    int DCERPC_RESERVED_1 = 0x08;
    /**
     * Supports concurrent multiplexing flag
     */

     */
    int DCERPC_LAST_FRAG = 0x02; /* Last fragment */
    /**
     * Pending cancel flag - indicates cancel was pending at sender
     */
    int DCERPC_PENDING_CANCEL = 0x04; /* Cancel was pending at sender */
    /**
     * Reserved flag for future use
     */
    int DCERPC_RESERVED_1 = 0x08;
    /**
     * Supports concurrent multiplexing flag.
     */