With the development of technology, e-book becomes more preferable for most people, it is a much easier way to provide people information and entertainment, just with some mobile devices like cell phone, iPad or Kindle, you can read books any time anywhere, no need to take a book along with you. There are many e-book formats available for choice, such as text (.txt), Hypertext (.htm or .html), Open eBook (.opf), Portable Document Format (.pdf), Palm Media (.pdb), DjVu (.djvu), EPUB(.epub) and more. Generally, PDF and EPUB are the two of most popular formats many people choose. Here is PDF and EPUB comparison - introduces the similarities and differences between them.
Open Standard
PDF is a file format created by Adobe System in 1993 for document exchange. PDF was officially released as an open standard in 2008 and published by ISO as ISO/IEC 32000-1:2008.
EPUB became an official standard of the International Digital Publishing Forum (IDPF) in September 2007, superseding the older Open eBook standard.
Readablity
Regardless of the application used to create them, PDF files can be viewed exactly the same way as origial format. If you convert a Word document to PDF, the converted PDF will look the same as orginal Word. On PC or Mac Os, PDF is perfect for readers. However, cases not always happen the same in mobile devices. As .pdf text is not reflowable, it will not resize to fit each device or user setting when opening a PDF file.
EPUB is totally different. It is designed for reflowable content, so that you can adjust the book content to fit the reader screen. For the readability with mobile devices, EPUB is better than PDF.
Populartiy
Accoring to Adobe official website. "More than 150 million PDF documents publicly available on the web today, along with countless PDF files in government agencies and businesses around the world." In this case, EPUB is not yet as popular as PDF. But it is hard to say what will happen in future, right?
Multiplatform
As PDF and EPUB are open standard, just with a right reader, both PDF and Epub can be viewable in multiplartform: Microsoft Windows, Mac OS, Linux and many mobile devices like iPad and Kindle.
Extensibitly
"More than 2,000 vendors worldwide offer PDF-based solutions including creation, plug-in, consulting, training, and support tools." From Adobe.com. PDF is more extensible that EPUB.
Security
PDF is well known for its security feature. Not only the digital signature allows you to proclaim the authority of the PDF files, but also the open password and owner password set to the PDF can protect others from copying and printing, even opening. This is one reason for why there are so many PDF files used in governments and businesses.
EPUB files can be optionally contain DRM, but it is not a requisition.
Interactivity
PDF users can easily create a PDF bookmark or add links to it, so that you can easier to navigate to particular pages or get access to Internet through PDF. Meanwhile, PDF users can also create interactive PDF forms. All we need is Adobe Reader.
EPUB does not support interactivity, it is read-only.
Each format has its own advantages and disadvantages. Readers and publishers can make their own decision after comapring PDF and EPUB. For example, the handy built-in application iBooks on Apple iPad (iPhone, iPod Touch) supports only EPUB. If one wants to read PDF with iBooks, PDF to EPUB conversionis necessary. But PDF is still the most popular ebook format around the world.
