By Manuel Lemos

AJAX is used by many Web applications to send requests from the browser to a Web server to store or retrieve information that can be used to update the page dynamically without requiring that the page be reloaded.

One type of application of AJAX is to display folders that may contain files or other folders inside them. When the user clicks on a folder, an AJAX request is sent to the Web server using JavaScript to retrieve the files and folders it may contain to be displayed on the page.

Check this PHP package that sends AJAX requests using jQuery to dynamically update listings of folders to display them in a tree view.