what is the difference between Raja Yoga and Hatha Yoga?

Raja Yoga prescribes to a particular meditative system, which focuses on the analysis and control of the field of human consciousness. Often known as the 'royal road' or the 'royal path' ('raja' in Sanskrit denotes 'king' or 'royal'), it offers a comprehensive method for controlling waves of thought by channeling mental and physical energies into spiritual energy. Hatha Yoga attaches a lot of importance to the perfect physical form, believing it to be a way of attaining spiritual perfection. And to this end it takes the help of pranayama (breath-control exercises) and mudras (hand gestures) to attain self-realization.  more