The liṅga, a rounded column usually set in a base, is the principal form in which Śiva is worshipped in temples and homes. It is understood as a sign of the formless absolute and of creative power, and myths tell of a pillar of fire without beginning or end.
Liṅga
The sign or emblem of Śiva, an aniconic form in which he is worshipped.
Also: Lingam