in·tro·duc·tion 
(ĭn′trə-dŭkshən)
(ĭn′trə-dŭkshən)n.
1. The act or process of introducing or the state of being introduced.
2. A means, such as a personal letter, of presenting one person to another.
3. Something recently introduced; an innovation: "He loathed a fork; it is a modern introduction which has still scarcely reached common people" (D.H. Lawrence).
4. Something spoken, written, or otherwise presented in beginning or introducing something, especially:
a. A preface, as to a book.
b. Music A short preliminary passage in a larger movement or work.
c. A basic introductory text or course of study.
[Middle English introduccioun, from Old French introduction, from Latin intrōductiō, intrōductiōn-, from intrōductus, past participle of intrōdūcere, to bring in; see INTRODUCE.]