A Case Study is basically a method for doing research. It is usually used in social sciences and also other related subjects.
The case study method of research uses an in-depth, longitudinal examination of a single instance or an even which is called a case. Thus, a case study provides the reader with a systematic outlook for everything.
It is a research study that makes an empirical inquiry for investigation about something within its real life content.
A case study is an elaborate empirical study of a phenomenon which helps in confirming or confuting the ideas, theories, logic and predictability behind it. Case studies are direct, practical, purposeful ways of diagnosing the problem areas and delving the success of the remedial measures undertaken. The dilemmas are discussed and students get ample scope to form their opinions after getting a direct feel of the real situation in the class room. However, the downside is that things can not be generalised on the basis of a case study, especially in the realm of social sciences, for various exogenous factors do not remain constant nor can they be made to remain constant either.