During the initial push for global computerization, 1970, in this case, the ISBN (International Standard Book Number) system was born. Its pioneer was a British bookseller that took the forward-looking step of computerizing its distribution operations. If you're an independently published author researching how to get an ISBN (or why to do it), it's crucial for the success of your book. While some books are published without ISBNs, the vast majority have them for many important reasons. The ISBN system is the basis for the global book supply chain, and books published without one are at a disadvantage.
Booksellers are among the chief reasons to have an ISBN for your book. The format of their databases connects the number with vital information about a book, including its price that is needed for scanning at checkout. It's also wise to view an ISBN as a marketing investment because it adds credibility and professionalism to a book and its author. If you don't have one, you'll be asked why not. The number also differentiates your book from others with similar titles. It helps avoid confusion and makes sure you come up correctly in searches when someone is trying to find out more about your work.
Speaking of searches, search engines prefer ISBNs because they provide clarity and accuracy. They want to identify your book correctly, and if there are others with similar titles, the unique number you are assigned will make sure only you come up in the right searches. Library cataloguers have been on board with ISBMs since their earliest days. They eliminate confusion by definitively stating in a standardized manner that one book is different from others. Because thousands of books are published each week, some have close-sounding titles and topics. Without numbering, a book can be mistaken for others.
Publishing industry databases such as Books in Print also rely heavily on ISBNs for their systems. It's a subscription service used heavily by booksellers, large library systems, search engines, and many others. It's also vital for an independently published author to be listed as the book's publisher because if you do it through a self-publishing platform and they are listed, many database users will exclude the books. Information about the ISBN application process is readily available online, and it varies by country. It is free in some places and carries a fee in others. But whatever the case, get an ISBN.