Final answer:
A statement detailing an organization's purpose, including its functions and services, is known as a mission statement.
Step-by-step explanation:
A statement that sets forth an organization's or department's purpose, including definitions, productions, and services, is best called a mission statement. A mission statement articulates the company's core objectives and approaches to reach those objectives, providing a guiding light for the goals and day-to-day operations. In comparison, a vision statement outlines the future aspirations of the company, a goal statement is more specific in nature detailing particular objectives to be achieved, and a purpose statement can be found in different contexts such as personal goals for instructional projects or college admissions essays.