Hello Yogesh,

As you asked about the term astrophysics , So it is a branch of space science that applies the laws of physics and chemistry to explain the birth, life and death of stars, planets, galaxies, nebulae and other objects in the universe.

On the other hand , you'll find astrophysicists working in oil exploration.  Astrophysicists are also heavily employed by the defense industry.

Hope it helps .

Thank you :)