The control <asp:UpdatePanel> is a standard ASP.NET control, which becomes available when you download the AJAX Extensions. This being said, it is not a Telerik's control and it stays the same, no matter you upgrade your Telerik's RadControls suite. It is used for asynchronous update of parts of the page. When you use it, you should use triggers to determine the exact update setup.
Very similar to the standard UpdatePanel is the RadAjaxPanel but its usage is much easier and intuitive. You can find more information about it here
. Working online demos are available on the link Shaun has provided.
the Telerik team