There are two ways to study.One is which is followed by almost every Indian student as that is how our education system is and that is to come back home and re read/study what you learned in class.I followed this too when I was in school and medical school up until I came to USA.
The system followed here is that you actually prepare for the lecture before you attend that lecture. This, I feel is better because :
You will retain better
You will never lag in covering what has been taught
You can ask questions which are more relevant and you won't be afraid of asking a question (I have seen professors insulting and being condescending while answering g questions). You don't need out of class time from your professor.
I am not saying you need to memorize everything but give it a read once.Come back home re read your class notes for the lecture and repeat the cycle for the next day's lecture.
Hope this helps!
Neha Rastogi, 6+ years working as a doctor
Source: Quora Digest