According to the Natyasastra, the art of classical dance into three broad divisions: nritta- pure dance, nritya - abhinaya and natya - which is a combination of both.

The fourth chapter of the Natyasastra is devoted to the karanas. It refers to the 108 karanas, dance postures, which are formed by the combination movements of the hands and feet. The Natyasastra further prescibes that foot movements used for the exercise of sthanas (position) and charis also apply to these karanas.

Nritta has been defined : Nrittam talalayashrayam

Pure dance whose constituents are, taal and laya - time measure and rhythm. In nritta the emphasis is on pure dance movements, movements for their own sake, creating patterns in space and time.

Nritya - abhinaya - expressional aspect.

Abhinaya is one of the most important aspect of bharathanatyam, which conjures up a fascinating world of imagination. A sanskrit term , abhinaya means to educate, or convey to the audience.The Abhinayadarpana-a sanskrit text by Nandikeswara- mentions that the actors educate the spectator by stimulating in him the latent possibility of an aesthetic experience.

Natya is a combination of nritta and nritya with a dramatic element to it. It is the dramatisation of a theme. The themes that are in the repertoire of Bharathanatyam generally are mythological stories, which sing praises of the deeds of the various Hindu Gods. The themes also consist the innumerable stories of the kings of different eras in whose praise many a great poets have penned beautiful songs. Natya is thus the visual painting that the dancer draws to get the story across to the audience.