An ISBN, or International Standard Book Number, is a number that uniquely identifies all books published worldwide. Valid ISBNs consist of 10 or 13 digits preceded by the letters 'ISBN'
10 digit ISBNs were used up to 2006
13 digit ISBNs were introduced from 2007
Differences between 10 digit and 13 digit ISBNs -
13 digit ISBNs began with 978 as first 3 additional digits
Next 9 digits would be the same
Last digit would be different
Example -
81-89746-01-4
978-81-89746-01-8