Savasana nidra

This is a savasana nidra, or yoga nidra practice.

what is yoga nidra?

Yoga Nidra literally means yogic sleep.  It is an ancient technique where the practitioner enters the deep states of conscious relaxation.  It is a systematic practice of moving awareness from our external world to the inner world.

It brings us to a state of deep sleep where our senses, intellect, and mind relax. We become free from the concepts of time, space and reason. When this happens, brain activity reduces and the body goes in the healing state. Therefore, it is also said that one hour of yoga Nidra can give the same benefit of a four-hour sleep. As the body enters a healing state, you can clear up the toxins at a cellular level, refresh the mind and remove baggage from the subconscious.

taken from

https://www.arhantayoga.org/blog/what-is-yoga-nidra