Mantras contain sounds grasped from Ether by the Rishis, Sages.
These sounds in the written form are called Aksharas.
This corresponds to Alphabets, yet more than Alphabets.
The specialty in Sanskrit is that the term Akshara means limitless, A+Kshara.
Sound is limitless.
The basic sounds according to Hinduism are,
A, that raises from the Mouth,
U, raises from the Throat and
M raises from the pit of the stomach.
Correct pronunciation can be from Sanskrit letters.
These three sounds are the basis of life and Motion.
The galaxies hum this sound.while in Motion and they are constantly in Motion.
Please read my article on this.
These three sounds make the Pranava OM/AUM.
Each God is assigned the Aksharas.
Shiva has five Aksharas assigned to Him.
This is called the Panchakshara.
The letters are,
This mantra is a maha mantra and is kept as a secret in the Sri Rudram in the Veda.
The intention is not to prevent some from knowing it, but enable one who is spiritually qualified and has the welfare of the world at heart.
The Panchakshara Mantra of Lord Shiva, like Mantras in general and the Maha Mantras in particular will not yield good results, but might yield unpleasant ones, if chanted by one who does not fulfil the above mentioned criterion.
These Maha Mantras are to be taught by a Guru in person, not Online.
And there are strict procedures including Diet, daily routine and behaviour.
How is Maha Mantra, Panchakshara is protected and kept secretively in the Vedas?
The name of Shiva , the Panchakshara is in the Yajur Veda.
‘The Middle portion of the fourth Kanda has a middle portion.
The Fifth Prasna.
This is Sri Rudram.
In the middle of the Sri Rudram occurs the name of Shiva,
In the Middle of this ( when written in Sanskrit), lies the name of Siva, the two letters of Shiva.
This is called the Jiva Ratna, The precious Jewel of Life
Shiva pooja is a difficult one to perform.
The Panchakshara of Shiva is to be initiated by a Guru.
There are Five Types of Panchaksharas.
3.Karana ( Active/submission by senses) Panchakshara.
4.Mahakarana( senses and their roots) Panchakshara.
For Tamil Readers.
நமசிவாய = ஸ்தூல பஞ்சாட்சரம்
சிவாயநம = சூட்சும பஞ்சாட்சரம்
சிவாயசிவ = கரண பஞ்சாட்சரம்
சிவாய = மகா கரண பஞ்சாட்சரம்
சி = முக்தி பஞ்சாட்சரம்