I think corresponding author can be any one who has helped u to complete ur manuscript... But main author is one who has worked on the research or completed the manuscript...
Works at Senior Consultant Author has 173 answers and 233.5K answer views4y
Normally, the first author is the person who did most of the work and took all initiatives including writing the first/second draft of the paper. He is the best person to answer if there is any query after the paper is published. Even during the refereeing process, this person (i.e., the corresponding author) has to answer to the Editorial Board of the concerned Journal. In some cases, the researcher is the first author, but the supervisor becomes the corresponding author - as he thinks that he could better respond.
Although the above “norm’ is more or less followed in the Western World, it is always not the case in India. Here, for promotions & other reasons, the Supervisor of the research team puts his name or name of somebody name of his choice (so that this other person could take the benefit of going to a Conference, promotions, Impact Factor Weighting, etc in his favor).
This is the reason of “frustration” among many young researchers. Also, the situation in Higher Education field in India is quite complicated and they do not follow the “NORMS” all the time - or, rather resort to unethical practices in many cases.