What does JavaScript use to send and receive data asynchronously?

JavaScript utilizes AJAX (Asynchronous JavaScript and XML) to send and receive data asynchronously. AJAX is a technique that enables web pages to communicate with servers without requiring a full page reload. This allows for a more dynamic and interactive user experience, as data can be updated and displayed on the page without interrupting the user’s activity.

AJAX works by using the XMLHttpRequest object to send HTTP requests to the server. The server can process these requests and send back data, which JavaScript can then use to update the web page dynamically. This asynchronous nature means that JavaScript can initiate requests and continue executing other code while waiting for a response, enhancing the performance and efficiency of web applications.

The other options, while sometimes related to the data transfer process, do not directly represent the method used for asynchronous communication in this context. JSON is a data format commonly used for sending data, often in AJAX responses, but it does not facilitate the asynchronous process itself. XML is another data format that was traditionally used with AJAX; however, it is less common today in favor of JSON due to its simplicity and ease of use. HTTP is the underlying protocol for communication on the web but does not encapsulate the specific asynchronous nature that AJAX provides.