Performing an audit, in reality is, about giving another party or party's assurance. An assurance engagement is one where a professional accountant evaluates or measures a subject matter that is the responsibility of another party against identified criteria and expresses a conclusion that provides the intended user with a level of assurance about the subject matter. Required: Explain each of the terms or phrases given in bold above in the context of: 4.1 Statutory external audit 4.2 Internal audit of a public company's internal control systems 4.3 VAT audit performed by SARS. (6)