Statutory interpretation is the process by which courts interpret and apply legislation. Some amount of interpretation is often necessary when a case involves a statute. Sometimes the words of a statute have a plain and straightforward meaning. But in many cases, there is some ambiguity or vagueness in the words of the statute that must be resolved by the judge. To find the meanings of statutes, judges use various tools and methods of statutory interpretation, including traditional canons of statutory interpretation, legislative history, and purpose. In common law jurisdictions, the judiciary may apply rules of statutory interpretation to legislation enacted by the legislature or to delegated legislation such as administrative agency regulations.