When you are using pages as your building blocks for WPF development, hyperlinks are a useful way to move onto different pages.
That has been proved of course on the internet for many years
As to why you might use pages, see a previous blog.
A hyperlink in the xaml world is similar to the anchor tag in html, in the respect that it goes inside relevant other tags.
For example, to add a hyperlink to a textblock, specify the hyperlink inside the textblock:
<TextBlock>My test is going to be <Hyperlink NavigateUri=”chelsea.xaml”>chels</Hyperlink> and their lack of Deco
That specifies the hyperlink, and when you click on it the NavigationService will move to the chelsea.xaml page