OnFocusEvent or IFocusable ?

I have seen an example of using the OnFocusEvent component to handle gaze, and how we can use the FocusEnter and FocusLost methods, as well as how to wire-up these functions in Unity...

But I wonder if this is just the old way of doing things or is it really different to using the common IFocusable interface and putting the code into its OnFocusEnter and OnFocusExit methods?

 

Sorry, my bad. I logged onto https://forum.unity3d.com/forums/hololens.102/ and then posted my question. Obviously, it did not actually log onto the link.