Lingam (Sanskrit: लिंगम्, IAST: liṅgaṃ, .lit sign, symbol or mark), linga, Shiva linga, ling or Shiva ling, is an abstract or aniconic representation of the Hindu deity, Shiva, used for worship in temples, smaller shrines, or as self-manifested natural objects. In traditional Indian society, the linga is seen as a symbol of the energy and potential of Shiva himself.
The lingam is often represented as resting on yoni (Sanskrit word, literally "vulva", "origin" or "source"), a symbol of Goddess Durga in Hinduism.
The lingam is a column-like or oval (egg-shaped) symbol of Shiva, the Formless All-pervasive Reality, made of stone, metal, or clay. The Shiva Linga is a symbol of Lord Shiva – a mark that reminds of the Omnipotent Lord, which is formless. In Shaivite Hindu temples, the linga is a smooth cylindrical mass symbolising Shiva. It is found at the centre of the temple, often resting in the middle of a rimmed, disc-shaped structure, a representation of Shakti. There is an inclination to reduce the Shiva linga and Shakti yoni, the two main Tantric symbols of ascending and descending forces – which are often represented by upright conical stones for the Shiva linga and ring stones or basis for the Shakti yoni – to merely the male and female sex organs, which is but one of their many reflections, and their erotic glorification. There is a tradition of Tantric sexuality of mithuna which uses sacred sex as part of Yoga practice. But it is not the only practice of Tantric Yoga, much less the highest, and when done is integrated into a much larger array of practices.
Terracotta Shiva Linga figurines found in excavations at Indus Valley Civilization site of Kalibangan and other sites provide evidence of early Shiva Linga worship from circa 3500 BCE to 2300 BCE.