When I get JSON data through AJAX, Where does the data get stored?

I want to know the place where certain JSON data get stored when it's sent from server to client which exists in the different directory.

I am trying to build simple API which send JSON data from server side(port number:5001) to client side(port number:3000).

What I noticed doing this project is that http header and body is not the place where the JSON to be contained.

If so, how does JSON data get delivered to client side? I want to know what happen in code-behind.

Following is the code that I wrote to build simple API:

Client side code:

componentDidMount() {
    axios.get('localhost:5001')
      .then((result) => console.log(result))
      .catch((err)  =>  console.log('Error ocurred'));
}

Server side code(ASP.NET Core 2.0):

UserPosts result = new UserPosts();
                result.id = 1;
                result.Name = "jay";
                result.Password = "1004";
                result.Content = "This is text from the server";
                string json = JsonConvert.SerializeObject(result);
                context.Response.ContentType = "application/json; 
charset=utf-8";

                await context.Response.WriteAsync(json);

I expected that the JSON data named 'result' will be attached to HTTP header or body but it was not. When I checked the raw data of http body on the console, it was just html content.