An ISBN is a special number given to a book when it is published, so shops, libraries, and computers can tell that exact book apart from every other. The letters stand for International Standard Book Number. You usually find it on the back cover, near the barcode.

An ISBN is a special numberISBN是一組特別的編號 given to a book when it is published在一本書出版的時候給它 so shops, libraries, and computers can tell that exact book apart from every other好讓書店、圖書館和電腦能把這本書跟其他書分清楚 The letters stand for International Standard Book Number這幾個字母代表International Standard Book Number（國際標準書號） You usually find it on the back cover你通常會在封底找到它 near the barcode就在條碼附近

A hard cover and a paper cover of the same story can have different ISBNs, because they are sold as different products. A new edition can get a new number too.

A hard cover and a paper cover of the same story同一個故事的精裝版和平裝版 can have different ISBNs可以有不同的ISBN because they are sold as different products因為它們是當成不同商品在賣 A new edition can get a new number too新版本也可能拿到新的編號

Magazines and journals use a sister number, an ISSN, not an ISBN. Though actually, not every printed thing has one — a school worksheet, a family photo book, or a tiny pamphlet may never get a number. And the barcode you scan is not itself the ISBN; it is a machine picture of that number (with a little extra).

Magazines and journals use a sister number雜誌和期刊用的是另一組姊妹編號 an ISSN, not an ISBN叫ISSN，不是ISBN Though actually不過其實 not every printed thing has one不是每一份印刷品都有編號 a school worksheet, a family photo book, or a tiny pamphlet may never get a number學校講義、家庭相片書，或是一本小冊子可能永遠都不會有編號 And the barcode you scan is not itself the ISBN而且你掃描的條碼本身並不是ISBN it is a machine picture of that number它只是那組號碼的機器圖像 (with a little extra)外加一點額外的東西

In speech people just say the four letters. It is a shop-and-library word, not a poetic one.

In speech people just say the four letters講話的時候大家就直接說這四個字母 It is a shop-and-library word這是個書店和圖書館用的字 not a poetic one不是什麼詩意的詞