is it possible to update an iOS app by XML files?

is it possible to update an iOS app by XML files?

I am really new in app design, and do not know how can I add content to my
app after is it out. In my app I have music and video pages. I was
thinking how can I add new music or videos to the app later ?! So it is
possible to link the content to an xml file and keep the xml in a host.
Therefor, to update add the app, I edit that xml file and when user loads
the app it shows the XML contents? Is it actually how apps works? If this
way works, or there are better ways to do it, please let me know.
Thanks