The 'caph.focus' is an AngularJS module which provides functionality to navigate the focusable elements using the remote controller which is a main input device of TV. It consists of 3 parts: the 'focusable' directives which represent focusable elements, the 'nearestFocusableFinder' which is in charge of searching for the nearest focusable elements, and the 'focusController' which provides the focus related behaviors.
Samsung SmartTV & AngularJS - Check Here