Swamigal, Siddhargal, Munivargal and Rishigal

Rajasekar : Siddhars are saints in India, mostly of the Saivaite denomination in Tamil Nadu, who professed and practised an unorthodox type of Sadhana, or spiritual practice, to attain liberation. They are Siddhas because they attained siddhi, i.e. "power, prowess, strength, ability", a special kind of psychic and supernatural, miraculous, occult power. According to Thirumoolar: "Those who live in yoga and see the divine light and power through yoga are the siddhars (Tamil Chittar)".

Siddha Tombs (Memorials) are known as Jeeva Samadi. Jeeva or Sajeeva / Jiva / Samadhi means "becoming one" with the universal consciousness or merging with the Divine. This is a state where Siddhas enters into the samadhi state at their own will after completion of their mission on earth and their mind completely dissolved into the Divine, They stop the functioning of the body and mind.

Lingesh : There are 18 siddhars in the Tamil Siddha tradition. They are....

Thiru Patanjali Siddhar

Thiru Agastya Siddhar
Thiru Kamalamuni Siddhar
Thiru Thirumoolar Siddhar
Thiru Kuthambai Siddhar
Thiru Korakkar Siddhar
Thiru Thanvandri Siddhar
Thiru Konganar Siddhar Thiru Sattamuni Siddhar
Thiru Vanmeegar Siddhar
Thiru Ramadevar Siddhar
Thiru Nandeeswarar (Nandidevar) Siddhar
Thiru Edaikkadar Siddhar
Thiru Machamuni Siddhar
Thiru Karuvoorar Siddhar
Thiru Bogar Siddhar
Thiru Pambatti Siddhar
Thiru Sundarandandar

One who is pure in heart is never attracted by the external energy, which urges the individual soul to try to dominate material nature. The is said to be muni.  The word muni means "thoughtful." A devotee is as thoughtful as a nondevotee is speculative. The nondevotee's speculation is impure, but a devotee's thoughts are pure.  The name Agastya Muni is very significant. Agastya Muni represents the mind. The word agastya indicates that the senses do not act independently, and the word muni means "mind." The mind is the center of all the senses, and thus the senses cannot work independent of the mind.

Zackir : If you phrased your question "What's the difference between Swamigal, Munivargal and Rishigal?" I have some thoughts on that!!

Instead you asked "What's the FUNDAMENTAL difference".... which doesn't exist (spiritually). They are all one to which they belong.

A superficial difference in my opinion....

Swamigal : Swam means wealth. Swami means wealthy. Wealth here is not material wealth.  It's the divine itself.  We are His wealth and He is our wealth. Cannot be separated and Should not be separated.  So all of us are Swamigal in that sense. In the Malay culture, a wife calls her husband "Swami". In Malay, Swami means proprietor; meaning to say, husband has proprietory right over his wife

Rishi : Ris is ascension. Rishi is one who has ascended and received the divine knowledge directly from the divine.  There are unknown levels or stations of ascension (I don't have any idea on how many) and on where they are, they are Devarishi, Brahmarishi, Maharishi......

 
Munivargal : The ones who are free in this world by freeing themselves from the world.  Unlike us, they are not caught between what has happened and what must happen. They are relieved of the past and future, such that their past doesn't decide them or their future.