There are not only several different levels of Samadhi, but also different ways to achieve Samadhi.
Samadhi is a state of consciousness described as a state of spiritual ecstasy in which the consciousness leaves the body.
There are several different levels of Samadhi and within them, even more grades.
You might be in a low level of Samdhi called Savikalpa Samadhi or one of the highest Nirvikalpa Samadhi.
In savikalpa samadhi, there are also levels.
At the Nirvikalpa samadhi level, the person is in a trance for as long as 21 days.
Sometimes they don't return to their body but their spirit leaves to the universe.
Many believe the feeling of ecstasy and power makes them want to dwell in the trance.
Sahaja samadhi is the highest level where the participant functions as one with the universe yet can function also on the earthly plane.
When in a higher level of consciousness, you have the ability to live prolonged periods without consuming any food.
It is the practice of eating air.
The body in the higher state doesn't need food.
The practitioner has the ability to sit long hours motionless.
There are tales of people found after hundreds of years in a trance.
Are these stories true? No one can say for certain but there are witnesses to much shorter prolonged trance periods.
A documented study on a yogi buried for eight days does have proof that they can survive for long periods in a trance like state.
They connected the yogi to an EKG, which showed that his heart stopped while in the pit.
Right before they dug him up, it restarted.
He was alive and well after eight days.
While in Samadhi the universe is visible to the person in the trance.
They are able to accomplish things in the trance they couldn't accomplish out of the trance.
Aside from the miraculous types of capabilities, the trance like state is beneficial for the body as well as the mind.
The calming effect negates much of the stress faced by individuals on a daily basis.
The brainwaves of those in Samadhi differ from those of a normal state and those of meditation.
It is deeper than traditional meditation.
Studies of the brain show a different pattern of activity from traditional meditation.
There are increased alpha waves and also a rhythmic theta pattern.
Yoga is one method of achieving the Samadhi state.
It's a state you learn but some people attain it naturally easier.
There is nothing magical about learning the capability to do so.
It simply requires practice and relaxation.
You cannot push to learn the skill.
That defeats the purpose and you find yourself exhausted rather than in a blissful state.
The ability doesn't occur right away but takes years of training to achieve the highest level.
Along the way, other levels of Samadhi are rewarding enough to make you want to strive higher.