Radha Ashtami, or Radhashtami, Radha's birthday is celebrated on the eighth day of the Shukla Paksha, during the waxing moon in the month of Bhadrapada August or September. In Brihad Gautamiya Tantra, Radharani is described as the direct counterpart of Lord Krishna, the primeval power of the Lord. The love of Radha Krishna is the symbol of the union of two souls, infinite and unconditional. Radha is the hladini shakti of Krishna.
In the religion of Hinduism, Radha or Radharani is the consort of Krishna the eighth avatar of Vishnu, as well as an important embodiment of Shakti, the divine feminine energy. The articulated Hindu symbolism, Radha represents the total devotion to God and abandonment to Him unconditionally.
The Itihasas tell us that Krishna spent his youth as a shepherd in the village of Vrindavan, surrounded and worshiped by the Gopis, the young cowherd who recognized him as the incarnation of the Supreme Personality of Godhead. The Gopis were deeply in love with Krishna, did nothing but think of him, enchanted by the charm and beauty that emanated, because of his divine nature.
Radha, the Gopis of all, it was the wisest and the most devoted to Krishna, who in turn showed a particular fondness for her. For this reason, in iconography Hindu, Krishna and Radha as Rama and Sita are portrayed together symbolizing the union of the divine masculine with the feminine principle.
In the traditional literature, Krishna represents the sun and Radha is compared in the light of the sun.