title_body: Can not Copy from a Pdf Document I am using Adobe Reader and Preview in mac to read a book in pdf format but I couldn't able to copy any word in the book. I don't understand what is different in this case because I have always done that on a pdf document so far. Any help would be great. Thanks
upvoted_answer: This sounds most likely that the document has been scanned, and then not processed with OCR (Optical Character Recognition). 
  
  Just with Adobe Reader and Preview.app, you can not do much about it. In order to make it copyable, you would have to get OCR software, or if you have access to Acrobat, use its OCR capability.
  
  There may also be some security settings with the file; you can see that by opening it in Adobe Reader, press  to display the document properties, and then select the Security tab.