How do file extensions work?

Question

Im wondering how they work... r they codes?

subquestion. I have Powerpoint 07. i made a powerpoint and i saved it as a 97-2003 and agian as 07. the 97-2003 file was 11MB and the 07 file was 1.5MB. how has the different file extensions compressed the powerpoint?

Answer 1

eh..........

r u sure tis happened??

its practically impossible for a same files with diff names to occupy diff amt of space.

P.S: What u r tlkin abt here isnt file extntns bt file names!! A$$!

Answer 2

Are the extensions the same? In other words, do they both end in .ppt as in 97-2003.ppt and 07-2003.ppt? It is possible to do a "Save As" on a file which may change the file type (and the extension). For instance, you can save a PowerPoint as a native .ppt file or as a a Web Page .html. They would have drastically different file sizes.



As far as how extensions work, they are cues to the operating system to use a certain application to open the file. For instance, double clicking on the file picture1.bmp would start the application MS Paint which in turn would open the file picture1.bmp.



By the way, Windows XP and Vista, by default, hide the extensions. You can view the extensions by starting file Explorer, click on Tools | Folder Options|View. Uncheck Hide Extensions for Known file Types.



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Okay, the new info helps. When you save as a 97-03 file , it saves it under the old format, which as you see is quite bloated. The new 07 PowerPoint saves it under the New MS Office 2007 .docx, .pptx formats which is based on xml. You wan't be able to view the the 07 formatted .pptx in older PowerPoint versions, unless you download the converters.



By the way, your question is fine.

Answer 3

The extension is basically just an identifier. You can freely change a .exe file to .zip, .txt, .ogg, whatever you want. It just won't work after you do. There are some exceptions to this rule (you can change a .cdr file to .iso and it will work), but only if the two file formats are written the same way. Really it just tells your OS how to handle the file, and what program to open it with.

Answer 4

"Wes M" told the right thing all other answers are foolish even this question itself. If you know something about file extension, then you never ask such a foolish question.