When you open a book, even-numbered pages on the left are called verso pages. ,The odd-numbered pages on the right are called recto pages. (The verso page is the back of the previous recto page.)
The vast majority of books follow the industry standard of the first chapter opening starting on a Recto, or right-hand (odd-numbered) page 1.
Often, a prior chapter ends on an odd-numbered page. When this happens, it is customary to make the back of that recto page (the verso) blank, to allow the next chapter to start on the correct page.
This is also true for many front matter pages like dedications and quotations.