Call this method if changes have occurred to the control and need to be sent to the client browser. This method updates the CallbackResults of the control to include the current state of the control.

The updated control contents do not automatically get sent to and displayed on the client unless the control itself initiated the callback. If the control did not initiate the callback, the developer must pass the callback results to the client via the initiating control. For example, if a custom tool allows the user to click on a Map control and the Map causes a callback, and during the callback the server-side code modifies the TOC (table of contents) control, the changes in the TOC will not be displayed unless its CallbackResults are copied to the Map control's CallbackResults. Use the CopyFrom or CopyTo method to copy these CallbackResults between Web ADF controls.

Reference