Lounge

Hi Sumita,
This forum is a social forum but people will generally answer specific questions or point you to a more appropriate forum in Moodle.
Your request for information was very general and could be answered by several thick reports or theses.
I would recommend that you do some research e.g. searching through Scholar.google or your university e-library for some relatively recent (5 years or so) but highly cited texts to derive the main concepts that can help you answer your research question. This will guide your further research that may involve in future you asking a specific question here.
While you are at Moodle.org you might like to read about the principles that underpinned the development of Moodle - search for constructionist.
Good luck.