What is a PDF?

“The more you read, the more things you will know. The more that you learn, the more places you'll go.”  - Dr. Seuss, "I Can Read With My Eyes Shut!"

If I ask did you ever download e-book and use? (Of-course I know you all have own that pleasure) did you notice that most of documents are PDF. So why PDF? There's many other file formats, countless. But why PDF? Because the true reason is most of publishers want there users should only be able to create and read, not edit. It's having become the de facto standard for documents.

PDF or Portable Document Format (PDF-Portable Document Format) developed by Adobe Systems. Yes they're also responsible for creating Photoshop software. When you want to read PDF document you require a PDF reader software, most popular one is Adobe Acrobat Reader (don’t worry it’s free).

 The Rise of PDF 

PDF released in the early 1990s. Including text formatting and inline images, early versions had no support for external hyperlinks. In 2008 Adobe released PDF 1.7, Adobe Extension Level 3 / Acrobat 9.0, this got the ISO standard ISO 32000-1:2008 

Specialized subsets of PDF

1. PDF/X - 2001 - series of ISO 15929 and ISO 15930 standards based on PDF 1.3, PDF 1.4 and later also PDF 1.6
2. PDF/A - 2005 - series of ISO 19005 standards based on PDF 1.4 and later also ISO 32000-1 - PDF 1.7
3. F/E - 2PD008 - ISO 24517 based on PDF 1.6
4. PDF/VT - 2010 - ISO 16612-2 based on PDF 1.6 as restricted by PDF/X-4 and PDF/X-5
5. PDF/UA - 2012 - ISO 14289-1 based on ISO 32000-1 - PDF 1.7