Nrtya  is that branch of the dance where the gestural expressiveness of hands, feet and body,  expressions and ideas meet together tuned with a particular emotion, bhava, in a certain melody, with a certain feeling, rasa, with the right rhythm, tala and beating, laya.
The nrtya aspect of the dance can be considered the blending of nrtta and abhinaya, typical of the natya, in which abhinaya is the central part.