Parallax examples (not mine)

I don't use the parallax effect - can't quite come up with good uses for me or how to implement them. Here are a few website examples from an article for ideas, (I've listed the actual article also). Probably not done with xara, but I'm sure xara has the capability of doing a lot of the same things. My first question is on the first site - the parallax effect is for the top layer to slide over the background layer - how do you this?

http://www.fluttuo.com/
http://davegamache.com/parallax/
https://nasaprospect.com/
http://www.cyclemon.com/

Actual article: https://uxplanet.org/10-must-see-exa...s-701e7f510113 - has more info and examples

Here is a guide to creating parallax in Xara:
https://xaratemplates.com/simple-par...b-designer-10/

Thanks. I have Designer prox v19, it has the parallax scroll animation, so I don't need coding, just examples on how to use it.