Chapter Summary

Ajax is a technique for sending and receiving data asynchronously in the background.
The data can be sent in many forms, but it is usually in JSON.
Ajax can be used for making partial page updates without having to do a full page reload.
Ajax can be used for communicating with external APIs.
Ajax requests can be made using the Fetch API.
The Response interface allows you to control the response received from a request or to create your own response objects.
The Request interface allows you to create a request object that contains information about the request being made, such as the URL and headers.
The Headers interface allows you to create HTTP headers that can be added to a request or response object.
Requests can retrieve data using a GET request, or send data using a POST request.
The FormData interface makes it easier to send data from forms.