I would like know if there is a database on the internet that I search
in order to get all the file type. For example, .Doc ->Microsoft Word
Document. PDF->Adobe Acrobat File etc. Is there a database on the
internet that keeps track of the different file types, what are they
(audio/text etc), and what application do they bleong to. I did try on
IANA, but the file types they have limited.

hilals...

Without a doubt, the most extensive database of file extensions
on the internet is FileExt.com, with a current database of 18,379
records for unique file extensions. Naturally all these extensions
cannot be listed on a single page. Their alphabetical index starts
on the following page, and there is a searchbox to look up a specific
extension in the top left of every page on the site:
http://filext.com/alphalist.php?extstart=%5EA

A one-page list of the most common filetypes can be found on
ComputerUser.com:
http://www.computeruser.com/resources/dictionary/filetypes.html

And a list of the most vulnerable filetypes (most likely to be
hacked or used in a virus) are found on this page at KarenWare:
http://www.karenware.com/powertools/filetypes.asp

 
Please do not rate this answer until you are satisfied that  
the answer cannot be improved upon by way of a dialog  
established through the "Request for Clarification" process. 
 
A user's guide on this topic is on skermit-ga's site, here: 
http://www.christopherwu.net/google_answers/answer_guide.html#how_clarify 
 
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Additional information may be found from an exploration of
the links resulting from the Google searches outlined below.

Searches done, via Google:

filetypes
://www.google.com/search?q=filetypes

"file types"
://www.google.com/search?q=%22file+types%22

Could

Thanks very much for the rating and the tip!

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