Which term describes the technique of requesting and reusing data using the XMLHttpRequest object?

• A. AJAX
• B. DOM
• C. API
• D. XML

Answer: (A)

AJAX is the technique of requesting and reusing data in the background with JavaScript, typically using the XMLHttpRequest object (or the modern fetch API) to communicate with a server after a page has loaded, then updating parts of the page without a full reload. This lets a web app fetch data asynchronously, reuse that data across the UI, and create a smoother, more responsive experience.

It’s called AJAX because it combines Asynchronous communication with JavaScript and often involves XML as the data format, but the data can also be JSON or others—the key idea is the asynchronous fetch and partial page update, not the specific data format. The other options refer to a document structure (DOM), a broad interface for software components (API), or a data format (XML), none of which capture the technique of fetching data asynchronously and updating the page.