Upasana is formed of the word 'asana' (sit) with the preposition 'upa' (near). The word, as a whole, signifies a spiritual act performed in prayerful proximity to God. It serves as a vehicle for an aspirant to climb up the spiritual ladder. In a way, it represents a mental attitude (bhava) which takes the aspirant towards self-realization.
Upasana is meant for obtaining freedom from ignorance and delusion, and is regarded as one of the means of purging oneself of the papa-s which might have been committed, independently or otherwise. The more one thinks of God, the more God-like one can hope to become. Very similarly, the more one thinks of worldly objects, the more worldly one would become. Upasana is the union of the spiritual aspirant (upasaka) with the one meditated upon.
In the main, upasana is of five kinds, and these are Vaisnava, Sakta, Saiva, Saura, and Ganapatya. They are of either a divya (divine), vira (courageous), or pasu (lower) nature. It is further classified as sattvika (pious), rajasika (active), and tamasika (ignorant), depending upon the aspirant’s inclination towards renunciation, towards personal enjoyment and happiness, or towards hurting others.
- The Encyclopedia of Hinduism