Om Namah shiva is a famous and important mantra of Hindu religion. Its translation is ‘salutations to Lord Shiva', which reveals the 'Om' devotion of the devotee first. The syllable "ya" at the end of the mantra denotes an offering. In this way Mantra 'Om Namah Shivaya' really means 'I honor Shiva with his name', and only 'I respectfully call upon his name'. 'Om Namah Shivaya:' Mantra is sung in the prayers for the Lord Shiva by devotees and yogis in meditation. This prayer is related to the qualities of divine love, grace, truth and happiness.
Traditionally, this mantra is beneficial and powerful for removing all physical and mental illnesses. Many Hindu teachers believe that the proclamation of the mantra is nectar for the health of the human body and for the soul.
This is called Shiva Panchakshara or Shiv Panchakshi, the most sacred greeting for Shiva, the five-letter mantra dedicated to Shiva (such as om leaving Om). In Pooja, chanting, meditation, havan, Shiva devotees can be recited by Panchashera and smearing Vibhuti on the body.
The Tamil Saivaite hymn Tiruvakkam starts with five letters ‘Na' 'Ma' 'shi' 'va' and 'ya'. This is a part of a Hindu prayer taken from 'Yajurveda', and thus, in the form of proper name of Shiva, Rudra (later Shiva) is addressed in the original context, where Shiva holds the root meaning of it. Is an adjective, which means 'auspicious, benign, friendly', is a decent form of Rudra.
In the tradition of Siddha Shaivism, the name Shiva is considered as the universal unity of Lord Shiva's Panch Bodha Tattva and his five elements:
'Na' sound represents the earth
'Ma' represents the sound water
'Shi' sound represents fire
'Va' sound represents the pranic air
'Ya' sound represents the sky
Its total meaning is that universal consciousness is one.