Predictive Astrology By Anju Anand

Bhava in Vedic Astrology
Bha means to Shine; the zodiac is called Bhachakra (shining circle) and is created by Bhaskara (Surya; the light creator).

Bhava means emotion, state of mind.

Bhavana – Imagination.

Meaning of Bhava From various dictionaries:
bhava coming into existence , birth , production , origin , arising or produced from , being in , relating to ; becoming , turning into (comp.); being, state of being, existence, life; worldly existence, the world Bhava i.e. Shiva and his wife.

meanings of "bhava":1.(at the end of comp.) arising or produced from
1.being; 2.birth; 3.source; 4.worldly existence; 5.the world; 6.well-being; 7.excellence; 8.name of Shiva;
Bhaava. becoming, being, existing, occurring, appearance; turning or transition into.

"bhaava": 1.being; 2.becoming; 3.state; 4.manner; 5.rank; 6.true condition or state; 7.innate property; 8.inclination or disposition of mind; 9.feeling; 10.love; 11.purport; 12.meaning; 13.resolution; 14.the heart; 15.existing thing; 16.a being; 17.abstract meditation; 18.conduct; 19.gesture; 20.birth; 21.the world; 22.the womb; 23.will;
This world is Bhava Sagar – (Ocean of Becoming), and hence the Mother Goddess Tara is called Bhavaani (A form of Paarvati, wife of lord Shiva) She who becomes everything and to  save us from this world of becoming, she takes the form of Bhav Taarini (Takes us safely from this ocean of constant becoming) .

And hence the Bhava is superimposed on Rashi.
In Western Astrology it is called as houses. The first house is the house which rises on the Eastern Horizon you will see a particular Raahi (Assuming you know, how to identify the star constituting the Rashi) rising (Ascending or climbing)
Suppose the rising sign is Vrishbha, it is - Lagna or Ascendant for the native taking birth at that particular moment