In (sort of) answer to the OP, it has been explained in previous GTs what the tyres compare to.
Comfort: Normal road tyres that you may have on a normal car - Comfort hards represent 'normal' tyres with comfort softs representing sportier tyres (say Michelins or Contis)
Sport: Track day or 'sport' tyres (anything from lower track tyres like Federals/ Westlakes (Sports Hard) all the way through to Pirelli Trofeo R (Sports Soft)
Racing: As the title suggests, racing slicks - in a variety of compounds as with real racing tyres.
This is, of course, based on the assumption that these models carry through from previous versions of GT to GT Sport.