Here the `app` variable will be an "instance" of the class `FastAPI`.

This will be the main point of interaction to create all your API.

### Step 3: create a *path operation*

#### Path

"Path" here refers to the last part of the URL starting from the first `/`.

So, in a URL like:

```
https://example.com/items/foo
```

...the path would be:

```
/items/foo
```

!!! info

* A particular program while it is **running** on the operating system.
    * This doesn't refer to the file, nor to the code, it refers **specifically** to the thing that is being **executed** and managed by the operating system.
* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.

  - author: Abhinav Tripathi - Microsoft Blogs
    link: https://devblogs.microsoft.com/cosmosdb/azure-cosmos-db-python-and-fastapi/
    title: Write a Python data layer with Azure Cosmos DB and FastAPI
  - author: Donny Peeters
    author_link: https://github.com/Donnype
    link: https://bitestreams.com/blog/fastapi-sqlalchemy/
    title: 10 Tips for adding SQLAlchemy to FastAPI
  - author: Jessica Temporal

Next, it 🤖 takes the first task to finish (let's say, our "slow-file" 📝) and continues whatever it had to do with it.

That "wait for something else" normally refers to <abbr title="Input and Output">I/O</abbr> operations that are relatively "slow" (compared to the speed of the processor and the RAM memory), like waiting for:

* the data from the client to be sent through the network

In contrast to a "**container image**" that is the stored static contents, a "**container**" normally refers to the running instance, the thing that is being **executed**.