“I have a plenty of ebooks purchased from Amazon.com. They are in Amazon cloud and can be lost/deleted by Amazon. I am wondering if I can transfer these Amazon ebooks to my laptop and let them remain in the cloud? Can I share those ebooks from laptop from my PC after I purchased the books?”
Well, you can back up the books on your computer but you should note each book you bought from Amazon is coded for each specific device when it was downloaded to – you can call this restriction as Digital rights management (DRM).
But you can still back up ebook on your computer hard drive – just copy them directly from the Kindle. But they will only work on that specific Kindle. Some people use this method to backup different versions of their books coded for different device. This won’t remove them from the cloud either. Those files can only be read on the Kindle they were downloaded to. They can’t be read by any other Kindle or app. In this sense, if anything happens to your Kindle, the backup is useless.
You can have another set of the books by installing Kindle for PC and downloading books from archives. Those books will be coded for your PC and are not viewable by any other Kindle or Kindle app.
But don’t worry too much. Amazon is a huge company and have many servers and I’m sure have a lot of protections and backups for their servers. Even if one failed, I’m sure there’s a protocol for restoring everything. With Amazon’s system, we can download a copy of a book to new devices up to the limit set by the publisher (default is 6 simultaneous downloads).
You can share books with Kindles registered to your Amazon account. For the 35% or so of books that are loanable, you can lend a book once to someone not registered to your account.
Source from Amazon Customer Discussions.
Also see:
How to Sync PDF Books to Kindle
How to Convert PDF to Kindle Format – MOBI or AZW with Calibre
What E-book Formats Does Kindle Support?
Source:
http://www.pdftomobi.org/can-you-transfer-kindle-books-to-pc/