taken from field

Specifies whether this Node should be a part of focus traversal cycle. When this property is true focus can be moved to this Node and from this Node using regular focus traversal keys. On a desktop such keys are usually TAB for moving focus forward and SHIFT+TAB for moving focus backward. When a Scene is created, the system gives focus to a Node whose focusTraversable variable is true and that is eligible to receive the focus, unless the focus had been set explicitly via a call to requestFocus().