introduction vs preface

introduction and preface both are nouns.

Word	Noun	Adjective	Verb	Adverb
introduction	Yes	No	No	No
preface	Yes	No	Yes	No

As nouns, preface is a hyponym of introduction; that is, preface is a word with a more specific, narrower meaning than introduction:

Other hyponyms of introduction include exordium, opening, foreword, prolusion, preamble, prolegomenon, prologue.

introduction (noun)	preface (noun)
the act of putting one thing into another	a short introductory essay preceding the text of a book
the act of beginning something new
the act of starting something for the first time; introducing something new
the first section of a communication
formally making a person known to another or to the public
a basic or elementary instructional text
a new proposal

introduction (verb)	preface (verb)
	furnish with a preface or introduction