There was not much of a distinction, although the use of the term "Catholic" is most often found in papal language as a method for asserting its own claims of universality. This is, however, much more true for the Church following the 11th c. reform movements than before it, and also as a means of emphasizing Western orthodoxy in contrast to Eastern heresy and schism.

In short, the semantic meaning of a modifier on "church" varies from text to text, and I would have to see the particular text (or at least the author) to give a definitive statement one way or the other.