1. An introductory section of a book or written work, typically written by the author or editor to explain the purpose, scope, or background of the work
The author wrote a detailed preface explaining the inspiration behind the novel.
O autor escreveu um prefácio detalhado explicando a inspiração por trás do romance.
2. An introductory remark or statement that precedes something
As a preface to my speech, I want to thank everyone who helped.
Como prefácio do meu discurso, quero agradecer a todos que ajudaram.