Yoga nidra is a state of consciousness between waking and sleeping, like the "going-to-sleep" stage. It is a state in which the body is completely relaxed, and the practitioner becomes systematically and increasingly aware of the inner world by following a set of verbal instructions. This state of consciousness is different from meditation in which concentration on a single focus is required. In yoga nidra the practitioner remains in a state of light withdrawal of the 5 senses with four of his or her senses internalised, that is, withdrawn, and only the hearing still connects to the instructions. The yogic goal of both paths, deep relaxation and meditation are the same, a state of meditative consciousness called samadhi.
Yoga nidra is among the deepest possible states of relaxation while still maintaining full consciousness. - Source: Wikipedia
Yoga nidra helps in relieving mental, physical and emotional tension.
Yoga nidra can bring joy into your life.
Yoga nidra helps in connecting to yourself in a deeper level.
Yoga nidra improves sleep and can reduce insomnia.