When it comes to Google's book search project, we must also mention Google's ultimate mission, which is to index all the world's information and make it universally accessible. These two steps are carried out simultaneously. Whether it's Google's search engine or its book search service, both are indexing information from around the world. To make this information more easily accessible to people, besides releasing it for free, sometimes Google needs to employ certain technologies. Take book search as an example: previously, we could only browse scanned versions of books. If we wanted to excerpt certain content, it was not easy. If Google can convert these books into plain text versions, then the problem can be solved. For Google, this is clearly not a technical issue.
Today, Google has announced the addition of a plain text reading mode to its book search. When you find a book in Google Book Search that is not under copyright protection (such as some classical masterpieces), you will see that you can read them in plain text format. Take Charles Dickens' "A Tale of Two Cities" as an example: