“Lord Shiva first manifested himself as a Jyotirlinga on the night of the, Aridra Nakshatra thus the special reverence for the Jyotirlinga. There is nothing to distinguish the appearance, but it is believed that a person can see these lingas as columns of fire piercing through the earth after he reaches a higher level of spiritual attainment. There are twelve Jyotirlingas in India and they are spread all over India.
As per Shiv Mahapuran, once Brahma (the God of creation) and Vishnu (the God of Preservation) had an argument in terms of supremacy of creation. To test them, Shiva pierced the three worlds as a huge endless pillar of light, the jyotirlinga. Vishnu and Brahma split their ways to downwards and upwards respectively to find the end of the light in either directions. Brahma lied that he found out the end, while Vishnu conceded his defeat. Shiva appeared as a second pillar of light and cursed Brahma that he would have no place in ceremonies while Vishnu would be worshipped till the end of eternity.
The jyotirlinga is the supreme partless reality, out of which Shiva partly appears. The jyothirlinga shrines, thus are places where Shiva appeared as a fiery column of light. Originally there were believed to be 64 jyothirlingas while 12 of them are considered to be very auspicious and holy. Each of the twelve jyothirlinga sites take the name of the presiding deity – each considered different manifestation of Shiva. At all these sites, the primary image is lingam representing the beginningless and endless Stambha pillar, symbolizing the infinite nature of Shiva. The twelve jyothirlinga are Somnath in Gujarat, Mallikarjuna at Srisailam in Andra Pradesh, Mahakaleswar at Ujjain in Madhya Pradesh, Omkareshwar in Madhya Pradesh, Kedarnath in Himalayas, Bhimashankar in Maharashtra, Viswanath at Varanasi in Uttar Pradesh, Triambakeshwar in Maharashtra, Vaidyanath Jyotirlinga at Deogarh in Jharkhand, Nageswar at Dwarka in Gujarat, Rameshwar at Rameswaram in Tamil Nadu and Ghushmeshwar at Shiwar in Sawai Madhopur district Rajasthan, 12th joytrilinga is Grishneshwar at ellora in aurangabad district Maharashtra.”