The Almighty, beyond comprehension of finite minds has been referred to by an infinite number of names through the universe, wherever intelligent life capable of worship of the Infinite Lord exists. One of these names, popular in South Asia is Shiv (Shiva).
The almighty beyond form and comprehension has also been worshiped in an infinite number of forms in the universe, some human, for the Lord everywhere has an infinite number of faces and forms too
Some hold that for ease of worship of human devotees, who wish to visualize the Lord in human form, the Lord appeared as the sage Shankar in Himalayas. Others hold that having attained the most advanced stage of yoga through worship of the Lord known as Shiva, the sage Shankar merged his soul and identity with Lord Shiva and was then known as Shiv Shankar. The true mysteries of Almighty are not known fully even to the loftiest of beings, the angels of heaven. Only He knows Himself. Nevertheless, for ordinary human wishing to worship the Lord as Shiva in human form, the name used is Shiv Shankar.
Some hold that the Sage Shankar has reincarnated many a times in Central Himalayas around the currently named districts of Nainital and Almora and that the most recent such appearance was as Baba Haidakhan (1950-1984, in public 1970-1984) also known as Babaji to devotees. Babaji recommended the value of reciting holy names as a path of spiritual attainment. The recitation of holy names aloud or silently without sound is known as Jap in Sanskrit tradition. It is a recommended practice across spiritual and mystic traditions of the world and elsewhere in the universe where life capable of recitation exists.
The recommended holy words or spiritual mantra by Babaji was
Om Namah Shivay
It means Almighty I praise thee (or offer salutations) as Shiva
Due to its Sanskrit words and somewhat difficult meaning some find this mantra difficult and perhaps you might like to begin with a simpler one. There is is a favorite of this author whenever one wishes to visualize the Lord in human form for worship. It is,
Jai Shiv Shankar
Its meaning is praises upon the Almighty as the Lord Shiv Shankar
If you choose this mantra for Jap then consider it in four syllables, with one syllable each recited with an inward or outward breath. Stabilization of breathing and thought is a necessary perquisite for deriving benefits of mantra recitation. The four syllables are
Jai- Shiv -Shan- Kar
This mantra is exceedingly simple and exceedingly beneficial, capable of raising mundane human existence to the level of gods. It can be practiced anywhere but lonely mountain or forest surroundings are the best for highest levels of attainment.
Note: For those new to this mantra and wishing to cultivate friendship with it, a good place to begin is some of the popular songs and dances it has been incorporated in ( skipping the commercial ones) A favorite of this author available to all on YouTube is