前言为背景介绍和问题的提出；

The preview is about background and questions that I research.

youdao

前言为论文的第一部分。

The forward is the first part of the paper.

youdao

她为一本食谱写了前言。

She has written the foreword to a book of recipes.

《柯林斯英汉双解大词典》

The law code of Hammurabi is available to us and there's a preface to it in which he basically explains why you should obey the rules that he now is laying down for you.

汉莫拉比法典为我们提供了证据,汉莫拉比在法典的前言中向我们解释了,为什么要遵守他颁布的法律

耶鲁公开课 - 古希腊历史简介课程节选