What is a half-title page?

Answer 1

In a book, it's the page that appears directly before the title page. It usually lists only the title of the book but can sometimes include other elements, such as the author's/authors' name(s), edition.

Answer 2

A half-title page is a page that typically contains only the main title of the book, often with no additional information or decoration. It usually appears at the very beginning of a book, before the full title page.