Shiva Lingam has three distinct parts which are considered as portions of Brahma, Vishnu, Shiva and Shree yantra is represented goddess Maha Lakshmi. The lower part represents Brahma, the middle Vishnu and the upper and the most prominent represents Shiva. Thus, Shivling represents all the three powers in one- as the Param Braham or Supreme Shiva.
Another interpretation considers Shivling to be divided in two parts â€“ Shiva and Shakti. The top part is considered Shiva and the yoni is considered to be Shakti.