Meaning

• The beginning or introductory portion that comes before the main text of a document or book.

  "The book included a brief preface by a leading expert in the field."

• An introduction, or series of preliminary remarks.

• The prelude or introduction to the canon of the Mass.

• A title or epithet.

Meaning

• To introduce or make a comment before (the main point).

  "Let me preface this by saying that I don't know him that well."

• To give a preface to.

  "to preface a book"