Mudras are symbolic gestures or position of hands, used symbolically in Buddha images and in practice to evoke particular ideas or Buddhas in the mind during Buddhist meditation or ritual.
Like symbols held by gods in Hindu art or by saints in Christian art, Buddhist mudras indicate the identity of a Buddha or a particular scene being depicted.
Mudras are also used in ritual meditation, especially in Tibetan Buddhism, to generate forces that invoke a particular Buddha or deity.
While there are a large number of esoteric mudras, there are ten main ones, of which five are most commonly used in Buddha images. Each of the Five Dhyani Buddhas is assigned one of the five mudras, with which they are invariably depicted in art.
Dharma Chakra Mudra
The Gesture of Turning the Wheel of Dharma or also Called Dharma chakra mudra, the thumb and index finger of the right hand stand for wisdom and method combined. The other three raised fingers symbolize the teaching of the Buddhist doctrine, which leads sentient beings to the paths of the beings of three capacities. The position of the left hand symbolizes the beings of the three capacities, who follow the combined path of method and wisdom. This mudra Is characteristic of Dhyani Buddha Vairochana. It is also a mudra of Lord Buddha while preaching his first Sermon at Sarnath.
The Gesture of touching the Earth (Bhumi Sparsa)
The right hand gestures pressing or touching the earth. The position of the left hand symbolizes meditation. Together, they stand for the Buddha's overcoming of hindrances while meditating on emptiness. this is characteristic mudra of Akshobhaya. This mudra of touching the earth commemorating Gautam Buddha's victory over temptation by the demon Mara.
The Gesture of Meditation (Samadhi Mudra)
The nerve channel associated with the mind of enlightenment (Bodhichitta) passes through the thumbs. Thus, joining of the two thumbs in this gesture is of auspicious significance for the future development of the mind of enlightenment. This is characteristic Mudra of dhyani Buddha Amitava or Amitabha
The Gesture(mudra) Supreme Accomplishment and Meditation
The gesture of the right hand symbolizes bestowal of supreme accomplishment. That of the left hand symbolizes meditation. Together, they stand for the Buddha's power to bestow supreme and general accomplishments on his disciples, while he meditates on emptiness. This is characteristic mudra of Ratna Sambhaba Buddha.
It is the gesture of fearlessness and protection, also combination of turning the Wheel of Dharma and Meditation. The gesture of the right hand stands for turning the wheel of Dharma, while that of the left hand symbolizes meditation. The two conjoined symbolize teaching the Dharma while in meditation on emptiness. This is The Characteristic Mudra of Dhyani Buddha Amoghasiddhi.