Office 2007 XML formats use compression technologies so files tend to take up much less disk space. Internal data storage of the Office XML Formats is segmented into discreet components—for example, embedded code is stored separately from the document content inside the file. Each component within a single file is compressed using ZIP compression technology. In addition to the compression of each document segment, the entire document is also compressed using ZIP compression. As a result, the sizes of Microsoft Office Word documents, Microsoft Office Excel spreadsheets, and Microsoft Office PowerPoint presentations are reduced. The amount of compression and size savings varies per file.
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