The curly braces syntax and the tag both define a data binding at compile time
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script> import mx.binding.utils.*; public function initBindingHandler():void { BindingUtils.bindProperty(myText, "text", myTI, "text"); } </mx:Script> <mx:TextInput id="myTI" /> <mx:Text id="myText" preinitialize="initBindingHandler();" /> </mx:Application>