Does Astrophysics and Astrophysicist are same and what's the different in study ?
A person who have studied Astrophysics and have done research in the field is called an Astrophysicist. So the subject is Astrophysics and who pursues the subject as a career is called an Astrophysicist.
In Astrophysics there are a whole spectra of topics to study such as-
- Stellar Astrophysics
- Astroparticle Physics
- Space time physics (Cosmology is a broad part and most of astrophysicist work on this field)
- Astrospectral Physics
- Astronomy
- Multiverse Theory
These are some of the broad fields of studies. Although the main portion of astrophysics is cosmology and as you some of the pioneers in the field are Stephen Hawking, Roger Penrose, Amal.K.Raychaudhuri (General Relativity and its application in Cosmology).
If you want to get an essence of Astrophysics then I would recommend you to read 'Astrophysics for people in a hurry' by Neil Degrasse Tyson. PDF's are available online.
To know more about Astrophysics visit the link below:
https://www.careers360.com/courses/astrophysics-course
I hope this answer helps. All the very best for your future endeavors!