When it comes to buying books, what is the difference between a box set and hardcover gift set.?

A gift set will be in matching sizes, cover material, paper quality, font, etc. with coordinated cover art, all by the same artist. It may have an preface or introduction in each book which is unique to that edition, usually by another author or respected critic.

A boxed set comes in a pasteboard box which fits the books exactly and makes them look nice. Expect both box and cover art to coordinate. Preface or intro may be unique to the set.

The text of the books themselves will be identical, unless the word "abridged" or "condensed" is used.

It is the same number of pages, just a different way to present the books,maybe a difference in price too.

Pamela is probably right, but I would check the contents of both. There may be extras in one that are not in the other. The gift set might be illustrated. The boxed set may have all the novels up to volume 5; but the gift set may have only vols. 1 to 3, or it may have been published later and include vol.6. The boxes set may be in softcover.

My but we're prickly today.