According to Tantra there are seven Bija_mantra with Aim, klim, Hrim being the most important ones. They are sound symbols like OM and are considered as the most potent words or the most important mantras of all time. Each Mantra is connected with a particular deity and particular spiritual powers according to some interpretations. These mantras are vey widely used by the professional priests and temples.

These sound variations have several mystical significances. Many texts interpret them in very diverse way. They represent the deities in one sense and are included in various other mantras as prefix. They are sometimes considered as representative of Bhuh, Bhuvah, Suvah world and the other world like Mahat, Janah, Tapah and Satya.