In yoga, mudrās are used in conjunction with pranayama (yogic breathing exercises), generally while seated in Padmasana, Ardhasiddhasana, Sukhasana or Vajrasana pose, to stimulate different parts of the body and mind, and to affect the flow of prana in the body.
Others developed as iconographical symbols for depictions of deities in statues and paintings.
Others were developed for non-verbal story telling in traditional dance.
In the Hevajra Tantra hand mudrās are used to identify oneself to the goddesses at different holy sites.
They are used in conjunction with holding the breath (kumbhaka) during pranayama.