In the widest sense, the term consciousness means the experiencing of mental states and processes. The body consciousness is purely neuronal. In the human body, consciousness is tied to an organisational structure of the brain. Brainwaves in the skin of the head can give a hint on the mental state.
Recent research with imaging methods shows that unusual neural activity patterns and neuroanatomic changes can develop as a result of long-standing meditation procedures .
From a philosophical standpoint, the theorem holds 'Cogito ergo sum'.
From an esoteric standpoint, consciousness is a characteristic which is a essential component of spiritual bodies. Here, up to 7 levels of consciousness are distinguished.
Here are up to 7 steps of consciousness (Bhumikas) differentiated .
In Hinduismus the highest consciousness is the CHIT of the Tapoloka, which is a form of energy from which ultimately the creation derives.
The Shivasamhita 5.47 teaches ' He who contemplates on sunya (void or vacuum or space), while walking or standing, dreaming or waking, becomes altogether ethereal, and is absorbed in the chid akasa.
Kashmir Shaivaism knows astill higher Chit and a Chit-Shakti of Sadashiva in the divine Satyaloka, the Parabrahman of hinduism.
The buddhist Yogacara sess the world as 'Only consciousness'(rigpa).