‘Raja yoga’ literally means the king of yogas. Raja Yoga is so-called because it is primarily concerned with the mind. The mind is traditionally conceived as the “king” of the psycho-physical structure which does its bidding.
The basic premise of raja yoga is that our perception of the divine Self is obscured by the disturbances of the mind. If the mind can be made still and pure, the Self will automatically, instantaneously, shine forth.
In raja yoga the mind is the instrument for looking inwards and uncovering the inner self. Raja Yoga aims at controlling all thought-waves or mental modifications. While a Hatha Yogi starts his Sadhana with Asanas (postures) and Pranayama, a Raja Yogi starts his Sadhana with the mind, although a certain minimum of asanas and pranayamas are usually included as a preparation for the meditation and concentration.
According to Raja-Yoga, the waves of the mind can be controlled by practice and non-attachment.
The word that signifies God is AUM. Raja yoga, is the royal path of meditation. As a king maintains control over his kingdom, so can we maintain control over our own “kingdom” the vast territory of the mind. In raja yoga we use our mental powers to realize the Atman through the process of psychological control.
Because raja yoga is the path of meditation, it is when practiced exclusively generally followed by those who lead contemplative lives. Most of us will never fall into that category. Raja yoga is, however, an essential component of all other spiritual paths since meditation is involved in the loving recollection of God, mental discrimination, and is an essential balance to selfless action.