Are Word 2007 file sizes compressed compared to Word 97?

[Ricky Tikkitavi]

I recently converted a Word '97 file to a Word 2007 file and was shocked to
see that the converted file is a little more than half the original file
size. Why the difference? Is there some sort of compression going on?

 

[Luc]

Ricky,
Yes they are, see this article:
http://office.microsoft.com/en-us/help/HA100069351033.aspx

 

[Terry Farrell]

Yes, A document in Word 2007 format is an XML file comprising many
individual files that are zipped together. You can see this if you take a
document *.docx and change it in Explorer to *.zip. Open the file in WinZip
and you Weill see the structure. The big advantages of this are size and
resilience.