Final answer:
Pages viewed in pairs when a book is open are called spreads, with the design often starting new chapters on odd-numbered right-side pages, sometimes leaving blank even-numbered pages.
Step-by-step explanation:
Pages are viewed in pairs called spreads. This term refers to two pages that face each other when a book or magazine is open. In a spread, one page is on the left and the other is on the right. Due to the two-side rule, new parts or chapters often start on right-side pages, which are typically odd-numbered, sometimes leaving the preceding even-numbered page blank.
This practice creates a visual and structural harmony in the layout of the book and is much like the back button in a web browser that takes you to the previous view. In design, two contrasting fields might be used on a poster, with images or content divided between the left and the right sections, creating a visual balance.