Well the question in the title basically sums everything up but to put it in more context...
I am trying to wrap my head around the relativistic Geocentric Celestial Reference System (GCRS). Reading the introductory documents such as IAU Resolution 2000 I notice they state that the GCRS is kinematically non-rotating with respect to the Barycentric Reference Frame. I've seen elsewhere as reference frames being described as dynamically non-rotating. I don't understand the difference.
It is not clear at all what they mean. Is the GCRS rotating or not? Any suggestions?
In the document, it is stated about being kinematically non-rotating in the introduction and mentioned about being dynamically non-rotating just before Eq. $24$. To be clear the document is just an example of where I have seen the terminology used. I am sure it will be used elsewhere.