introduction : a preliminary treatise or course of study — Webster
Introduction (also known as a prolegomenon) is a beginning section which states the purpose and goals of the following content. The introduction typically describes the scope of the content and gives the brief explanation or summary of it. — Wikipedia
Propaedeutics is a historical term for an introductory course into an art or science. The etymology of propedeutics comprises the Latin prefix pro, meaning earlier, rudimentary, or in front of, and the Greek paideutikós, which means “pertaining to teaching”. As implied by the etymology, propaedeutics may be defined more particularly as the knowledge necessary before, or for the learning of, a discipline, but not which is sufficient for proficiency. — Wikipedia
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