How does laravel handles the ajax request?

I am trying to understand how laravel handles the AJAX request under the hood. Does it parse the string to JSON object and coverts it the POST or GET fields? or is there another way to do so? By far my understanding is that it uses api middleware to handle those requests and then JsonResponse is the class responsible to replace the contents of the request. Or does it uses Guzzle to handle all the requests?

via Chebli Mohamed