In the yogic tradition Nidra is as well referred simply as a state of alert awareness. In that case, Yoga Nidra is simply an inner state of inner peace where the mind and the body are regenerated and vitalized.
Nidra literally means “sleep” in Sanskrit. A wider definition could translate this word as “rest” or “activeless” and can be associated with the idea of mind stillness.
You spend 8 hours a day sleeping.
The goal with yoga nidra is to influence what happens in your dream state.
Nothing mysterious or supernatural.
You can condition your mind to have a greater sense of awareness and action over your dreams and sleeping state.
When you dream you are active within the astral world.
So, what is the connection with yoga nidra?
With yoga nidra, you try to influence what happens in the astral aspect of your mind. You try to influence your dream state.
You simply try to have some form of impact over the way you relate to your emotions and dreams.
There are whole schools in Tibetan buddhism dedicated to the exploration and mastery of your dream state.
How can you apply these techniques in your modern life?
Well, unless you are ready to dedicate your whole life to it, you probably will only touch the surface of it.
However, it is an impact which can be extremely beneficial when trying to harmonize your emotions and for instance find a greater sense of inner peace.