Mudras

Mudras in Bharatanatyam are hand gestures which can have an extremely wide variety of meanings. Mudras may simply add to the beauty and form of the dance (Nritta Hastas) or can also have seperate meanings and emphasize expressions. In addition, some mudras are performed with one hand, and are called Asamyuktha Hastas, while mudras performed with two hands, and are usually combinations of Asamyuktha hastas, which are called Samyuktha Hastas- literally "Together" hand positions. Each hand gesture has a specified meaning, known as Viniyoga. The list of names for both Samyuktha and Asamyuktha Hastas are recited in a Shloka, or hymn, which lists all in order to an ancient vedic tune. In addition to the mudra, other aspects, including context and other movements are required to truly gain the entire meaning of a mudra. 

Etymologically, mudra is said to have the sanskrit root of "mud" which is said to mean "to give pelasure or delight in," quite fitting, as without mudras, the aesthetic beauty of Bharatanatyam would be greatly reduced. Since their origin in anceint India, these mudras have been used to "heal" in Vedic religions. Finally, the gestures are said to connect the emotions used in Bharatnatyam with the flow of energy in the art from, communicating ideas and presenting them in a cohesive manner.