Sage Patañjali prescribes eight limbs (aṣṭānga) of Rājā Yoga in the second pada of the yoga sūtras: yāma (restrictions), niyāma (observances), āsana (postures), prāṇāyāma (breath work), pratyāhāra (sense withdrawal or non-attachment), dhāraṇā (concentration or mindfulness), dhyāna (meditation), samādhi (realization of the true Self or Ātman). The combined practice of dhāraṇā, dhyāna and samādhi constitute saṃyama, the kinetic and spontaneous flow of attention and energy in the object of meditation.
Whereas dhāraṇā involves binding thought to an object, such as a candle flame, dhyāna involves meditation without the object in a state of trance that leads to an heightened awareness of one’s connectedness with the world, samādhi.
Dhyāna is a tool to gain self-knowledge, creativity and ability to concentrate. The practice of dhyāna frees the mind to explore creative variations and maintain adequate energy levels in the body throughout the day.