Ajna (?jña, , Sanskrit for 'command') is the sixth primary chakra according to Hindu tradition.
Description
The Ajna chakra is positioned at the eyebrow region and it has two petals, said to represent the psychic channels Ida and Pingala, which meet here with the central Shushumna channel, before rising to the crown chakra, Sahasrara.On the left hand petal is the letter 'ham', and on the right the letter 'ksham', the bija mantras for Shiva and Shakti respectively.Ajna is considered the chakra of the mind. When something is seen in the mind's eye, or in a dream, it is being 'seen' by Ajna.Residing in the chakra, according to some beliefs, is the deity Ardhanarishvara a hermaphrodite form of Shiva-Shakti, symbolising the primordial duality of Subject and Object, and the deity Hakini Shakti is also present in this chakra.In kundalini yoga, different practices are said to stimulate the Ajna chakra, including Trataka (steady gazing), Shambhavi Mudra (gazing at the space between the eyeb
Source:
http://en.wikipedia.org/wiki/Ajna