I read as
<redirect/> is an optional element which can be used to specify that the response is generated by the new view using redirect response rather than rendering the response as the current request. If we don't specify this element then the address bar shows the current page address even the response is generated by other page.
I have not understood what author meant. Why we have to use redirect within navigation-case of navigation rule within faces-config. Can you please advise. Any ideas, suggestions, links, resources, sample code highly appreciated. Thanks in advance