Nowadays PDF's(portable document format files) are most widely used format for Ebooks or related. This PDF's are some times password protected and gives access to user just to view or read, that means they will not give you the ability to copy the content like text or images. So if you want to copy the content you need password.
However there are several Portable Document files that needs password to read and get viewed. This time you will be in chain because you don’t have the password to open it.
