What is the primary advantage of using AJAX for web applications?

The primary advantage of using AJAX is that it allows web applications to update parts of a page without needing to reload the entire page. This is achieved through asynchronous communication with the server, which allows data to be sent and received in the background. As a result, only the specific content that needs updating is refreshed, leading to a smoother user experience. This method reduces loading times and minimizes the amount of data that needs to be transmitted, as only relevant information is processed rather than the whole web page.

This capability significantly enhances responsiveness and interactivity within web applications, allowing users to continue interacting with the page while new data is being fetched. For instance, in a real-time chat application, messages can appear without the user needing to refresh the browser, creating a fluid and dynamic experience.