Who is a Product Designer and what does he do on the example of the Western market?

Question

User interface

I often meet specialists who call themselves Product Designer, but I can’t understand exactly what they do and what they are responsible for. Also, if you know, please write about what Interaction Designer does.
How to position myself in the Western market, if I am engaged in designing mobile interfaces, UI and UX design, Visual Design. Working on product features - user experience, interaction, emotions, etc.

Answer 1

Yura Vetrov talks well about a product designer, here is a presentation for example:
www.slideshare.net/jvetrau/design-weekend-2014
First of all, he is a strategist, then a designer (in the simplest sense of the word).
Also a manager to everything else.

Answer 2

There is also a Product Manager. As far as I understand, a person is engaged in planning the further development of the product, i.e. not only UX, but also functionality. In essence, it comes down to looking out for competitors' products and creating tasks to do the same, constantly redesigning the design, etc.