Now I will briefly describe Savikalpa and Nirvikalpa Samadhi.
The term "Vikalpa" loosely translates as "attributed" or "supported"....like having a focal point or a crutch to reach higher levels of awareness.
So, I assume I am speaking to Hindus who have a basic grasp of their own language.
Savikalpa means WITH attribute or support and this means attaining Samadhi through a vehicle...like Bhakti for Lord Shiva...like focusing on a candle...like chanting "Om"...anything the mind can associate with as a mere representation of a transcendent Consciousness (Brahman).
It is seen as a precursor to the ultimate state...it is associated with the
Bindu Chakra located at the Pineal Gland, between the Third Eye and the Crown.
It is also called the "Makara Point" where the two nerves, Ida and Pingala merge and dissolve...flowing out through the nostrils upon exhalation.
At this place, there is a psychic knot called Rudra Granthi and before that is broken, one can still experience Samadhi, but it isn't lasting and not really intense...and one can still 'backslide' or come back down from it.
In Savikalpa Samadhi, there is still limited bliss and divine states of altered consciousness...but there is still the ego...still the emotions and still a
concept of God or an external, independent source of being.
Nirvikalpa Samadhi comes from adding the negative "Nir" and "Nir" means "not" or "without" so Nirvikalpa Samadhi means "not supported" or without attribute or condition.
This is when the Rudra Granthi is breached and Kundalini leaves the Bindu Chakra and goes into the Crown for FULL enlightenment, in which there aren't any concepts left anymore...there is no "Shiva" and no "God" and no "I" and then, one becomes totally absorbed...lost...immersed in Satchidananda...which is not only the bliss, but the ultimate truth (Brahman) and becoming one with the source (Chit).
I have experienced Savikalpa Samadhi but not Nirvikalpa Samadhi because I always rely the grace of Lord Shiva to get me there...that's not to say that Lord Shiva does not exist when you reach Nirvikalpa Samadhi because He still does...but any 'name' you give it will do...any 'form' you give it, will do...it doesn't really matter anymore.
Savikalpa = Saguna and Nirvikalpa = Nirguna
So, it all depends on the concepts of "Nama" and "Rupa"...name and form.
What we consider/conceive of Lord Shiva to BE is only just a miniscule representation of what He (or She or It or Nothing) really is and we
could say that Lord Shiva is truly "unknowable" and "inconceivable" as Brahman...as Purusha.
It is only through His Shakti...through Maya that we see the being with the attributes we usually associate with Lord Shiva...now, this is STILL Lord Shiva...but also only represents Lord Shiva...like a photograph represents a person, but it is not the person.
It is the Divine Mother, Maha Kali which enables us to become aware of the existence of Maha Kala...Lord Shiva, because Lord Shiva cannot be understood or approached in any other way - unless one is in Nirvikalpa Samadhi...it is only through Shakti that Shiva can be approached...so I also acknowledge the Divine Mother.
When the balance occurs between Lord Shiva (Shakta) and His manifested energies (Shakti) the transition results in a whole new form and way of being...we call that Ardhanarishwara...the Tantric merging of the three aspects of Shakti (Will, Action, Knowledge - Iccha, Kriya and Jnana) with the infinite potentiality, impetus and substratum of the universe (which is Shiva).
So, Lord Shiva is particularly very happy when you pay homage to his "better half"...
Anyway, my mind has gone totally blank after typing that...so here is where the transmission ends.