Odissi, also known as Orissi is one of the eight classical dance forms of India. It originates from the state of Orissa, in eastern India. It is the oldest surviving dance form of India on the basis of archaeological evidences. The classic treatise of Indian dance, Natya Shastra, refers to it as Odra-Magadhi. 1st century BCE bas-reliefs in the hills of Udaygiri (near Bhubaneshwar) testify to its antiquity. It was suppressed under the British Raj, but has been reconstructed since India gained independence. It is particularly distinguished from other classical Indian dance forms by the importance it places upon the Tribhangi (literally: three parts break), the independent movement of head, chest and pelvis and upon the basic square stance known as Chauka or Chouka that symbolizes Lord Jagannath. This dance is characterized by various Bhangas (Stance), which involves stamping of the foot and striking various postures as seen in Indian sculptures. The common Bhangas are Bhanga, Abanga, Atibhanga and Tribhanga.
(Source : Wikipedia)