Uploading of files should provide the popup window that people normally use when they handle files on their computer. Because it runs on their computer, it works fast and is familiar to them. It offers multiple file selection and preview of images.

Uploading of multiple files requires an upload queue, so the user can tell which files are completed, in progress or still to be done. A progress bar should be provided, especially for big files like video content.

AJAX is a tecnique used to refresh only part of a page, without reloading it. It highly enhances the user experience. You can use it for example to directly validate form field submissions without waiting to the user submits the entire form.

Try a combined file upload and AJAX demo.