The Sattwik Abhinaya consists of two elements complementary to each other.They are the Rasa or emotional flavour and the Bhava or the mood to suit a particular emotion. Rasa is the primary and most important  requirement  of nritya which may be interpreted as emotional  flavour or sentiment. The artist must seek to arouse this ecstasy  in the spectators so that his emotions and theirs may fuse and become attuned  to the spirit  of the drama.

Bhava is the secondary and complementary features. Bhavas may be of four kinds.

(a) Vibhava, which is again sub divided in to abalambanam and its accessory Udipan. Love in the Radha Krishna  dance may be expressed through the former, while the latter helps the mood  with the external aid of a moonlight setting.

(b) Anubhava expresses the effect of a mood such as the  ravages of anger or sorrow, or the rapture of love.

 (c) Vyavicharibhava  pertains  to the temporary changes of settings to fit in with the mood  of particular  scene.

(d)  Sattwikbhava consists of eight standardized movement  to express such  emotions  as joy, fear or disgust.

The main difference between the rasa and bhava is that while rasa depends purely on  imaginative transfiguration, bhava is more earthy for  it is concerned with  creating a mood through  physical media. Rasas  express the beginning of a sentiment  while bhavas complete or round  it off either through the agency of mana; the brain or of the sharira; the body or through an action such as the throwing of a stone. 

Every rasa has its accompanying bhava. There are nine rasas with an equal number of  complementary  moods