The ratio decidendi of a case refers to?

The term "ratio decidendi" is a Latin phrase that refers to the legal, moral, political, and social principles used by a court to compose the rationale of a particular judgment. Essentially, it is the underlying principle or reasoning upon which a court bases its decision. This principle or rule is binding and must be followed by lower courts in future cases where the facts are similar. It is a fundamental concept in the common law system and helps in the development of the law and ensures consistency in the decisions of the courts.