what is isbn and when searching for a book does it have to be the same?

ISBN is an abbreviation for "international standard book number."

An ISBN is specific to an edition and publication of a book. For example, Shakespeare's play Macbeth is published by 20+ publishing companies; each publishing company's version has a different ISBN number. Also, if any of those publishing companies updates their version for any reason, the updated version gets a brand new number.

As far as whether the ISBN has to be the same, a lot of teachers require that students get the very same ISBN because it ensures that all students will be on the same page in the book, and if you cite or reference a page number, it's going to be the same in all books. This is less important if it's a play, since you can simply look at line numbers.

Hope this helps and makes sense!

Yes. The digital version of a book will have a different ISBN. ISBN is a thirteen-digit numeral code that is used to identify books by their title, edition, binding, and publisher. Whether the publisher is just releasing a new edition of the same book, or selling it in a different format (such as going from print to ebook) it will be given a new, unique ISBN each time.

The ISBN is a 13-digit number (formerly 10 digits) that uniquely identifies books and related media published internationally. The purpose of the ISBN is to establish and identify one title or edition of a title from one specific publisher and is unique to that edition, allowing for more efficient marketing of products by booksellers, universities, wholesalers and distributors. To learn more about the ISBN, visit the official ISBN website.