There are two main systems of Yoga, Veda, Vedanta leaning on the Purusha or the Masculine aspect of the One Divine Reality and, Tantra, which leans on the Shakti or the Feminine side of the same One Divine Reality. There are in both the systems several paths that lead to the Divine Reality that is within, behind, beyond creation. Bhakti is common to both Vedanta as well as Tantra though in both it takes a slightly different hue and form.
In its essence Bhakti comes from the root bhaj which means to take joy in the Divine, in remembrance of the Divine, serving the Divine, giving oneself to the Divine, singing the names of the Divine, addressing hymns of praise and adoration to the Divine, prayers addressed to the Divine as an act of love and gratitude, thinking of and meditating upon the Divine, sravana (hearing or listening about the Divine), darshan (seeing the Divine form within and outside), manana (contemplation of the Divine and His ways and lila), nidhidhyasana (absorbed in deep meditation upon the Divine).
Bhakti is a matter of the heart, of the emotional being. It takes joy in forming a living relation with the Divine such as of the Divine as a Master (Swami), Teacher (Guru), Pita and Mata (father and mother), Mitra and sakha (friend and playmate), Beloved (priyatama). Through these the soul seeks union with the Divine and is the relation it choses, so is its final fulfilment.
Bhakti is of three kinds belonging to the different parts of our nature. There is a physical-vital Bhakti which is turned towards the Divine in distress or for what it can get from Him. It is tainted with desire and ambition and hence not useful for the purposes of yoga. Then there is a mental Bhakti that tries to know and understand the Divine which is a good beginning for the yoga. Finally there is the psychic or true Bhakti which is full of faith and self giving to the Divine, for the sake of the Divine and the joy of the Divine. This latter leads quickly to the Divine realisation.
The above applies mainly to Vedantic bhakti. The bhakti in Tantra consists of Mantra, especially beej mantras or seed sounds whose vibrations correspond to the Deity, Yantra (geometrical patterns) meant to symbolically respressnt the Deity, and Pooja, that is various forms of ritualistic worship to invoke and propitiate the Deity.
Here again we have three kinds of worship, outer with elaborate external rituals, inner or through the image in the mind, manasik bhakti, and spiritual or adhyatmik which is made up of offering one’s ego-self to the Divine Mother. The bhava, inner state, of bhakti can be pasu (animal like), veer (heroic) or daivic (godlike). Here too bhakti can be done for partial fruits and worldly benefits or for Moksha, the ultimate goal of liberation from Ignorance that the Divine Mother can grant to the sincere seeker.
Affectionately,
Alok Da