I am not sure if you are asking for a technical definition of PDF, an Arabic translation of PDF, or both. I will address both concerns:

1. The Meaning of PDF: Portable Document Format (PDF) is a proprietary file format owned by Adobe Systems for electronic documents. The purpose of this file format is to enable universal portability, i.e., once a document has been saved in this file format, it can be opened in any platform and, importantly, it will be displayed and can be printed exactly the way it was designed. Its design elements will not be lost, partly because the fonts are embedded in the document itself. In order to open the document, all you need is Adobe Acrobat Reader, which is a free download available at http://www.adobe.com. To save a document as a PDF file, one needs either Acrobat Writer or Acrobat Distiller, which are part of Adobe Acrobat (available for purchase).

To read up on PDF, you can visit some online glossaries, such as:

Web Services Glossary:

http://webservices.web.cern.ch/webservices/ClientDoc/Tutoria...


CNet Glossary:

http://www.cnet.com/Resources/Info/Glossary/Terms/pdf.html


TechWeb Encyclopedia:

http://www.techweb.com/encyclopedia/defineterm?term=PDF&Defi...


Here is what TechWeb Encyclopedia says about Acrobat technology::

http://www.techweb.com/encyclopedia/defineterm?term=Acrobat

"Acrobat:

Document exchange software from Adobe that allows documents created on one platform to be displayed and printed exactly the same on another no matter which fonts are installed in the computer. The fonts are embedded within the Acrobat document, which is known as a PDF (Portable Document Format) file, thus eliminating the requirement that the target machine contain the same fonts. The PDF Writer in Acrobat turns most DOS, Windows, UNIX and Mac documents to the PDF format by taking the print stream and converting it. The Distiller function takes more complicated PostScript files and creates PDF files."


ZD Webopedia has the following to say about PDF:

http://www.zdwebopedia.com/TERM/P/PDF.html

"Short for Portable Document Format, a file format developed by Adobe Systems. PDF captures formatting information from a variety of desktop publishing applications, making it possible to send formatted documents and have them appear on the recipient's monitor or printer as they were intended. To view a file in PDF format, you need Adobe Acrobat Reader, a free application distributed by Adobe Systems."


If you need more detailed information on the technology, visit Adobe Systems at http://www.adobe.com.


2. Translating the term into Arabic: The term is a registered trademark, owned by Adobe Systems. Adobe uses the term in English only, even in Arabic documents intended for Middle Eastern and North African users. To see what I mean, look at this official document created by Adobe Systems and hosted by FontWorld. This is a bilingual document. Pages 1 and 3 are in English, while page 2 is in Arabic.

http://www.fontworld.com/pdf3/fwacro1.pdf

Here is an excerpt from the Arabic page:

مع أكروبات إصدار الشرق الأوسط، يمكنك بسهولة تحويل الوثائق التي تحتوي على نصوص عربية إلى ملفات

Portable Document Format (PDF)

وبالتالي توزيعها إلكترونياً على مختلف أجهزة ونظم الكمبيوتر بحيث تحتفظ هذه الوثائق بشكلها الأصلي

Note: I broke the sentence in order to avoid misdirected text flow, which sometimes happens on ProZ.com when you have both Arabic and English in the same line.

Notice how "Portable Document Format (PDF)" is kept in English in the middle of the Arabic sentence.

I hope this answers your question.

If you are still interested in rendering the phrase in Arabic, try:

صيغة الوثائق النقالة

I am not sure if Adobe Systems would like that.

Fuad

Fuad has really covered the subject. I am just providing a couple of alternative translations to "portable":
جوالة
مسيارة
سيارة

Also, if you must write the acronym in Arabic, I suggest transliterating it:
صيغة الوثائق الجوالة (بي دي أف).

Alaa Zeineldine