A legal opinion, often referred to as a legal memorandum or lawyer's opinion, is a written document provided by an attorney or legal expert that offers their professional assessment and advice on a particular legal matter or issue. Legal opinions are typically requested by clients, businesses, or other parties seeking guidance on the legal implications of a specific situation or decision. These opinions can cover a wide range of legal topics and may be used for various purposes. 

Legal opinions typically include a detailed analysis of the relevant legal issues, citations to applicable laws or precedents, and the attorney's conclusions and recommendations based on their legal expertise. These documents help clients make informed decisions and navigate legal complexities.

Legal Opinion always consist of IRAC which is stands for Issue, Rule, Application, Conclusion 

It's important to note that legal opinions are not legally binding in themselves but serve as informed guidance. The weight and credibility of a legal opinion often depend on the qualifications and reputation of the attorney providing it. Clients should use legal opinions as a tool for making informed decisions and, when necessary, as supporting evidence in legal proceedings.