Previously, you can view only websites in your browser but, now you can open any file in your browser when file being index on Google results via Google doc.
- Microsoft Word documents
- PowerPoint presentations
- Microsoft Excel (.XLS and .XLSX)
- Microsoft PowerPoint 2007 / 2010 (.PPTX)
- Apple Pages (.PAGES)
- Adobe Illustrator (.AI)
- Adobe Photoshop (.PSD)
- Autodesk AutoCad (.DXF)
- Scalable Vector Graphics (.SVG)
- PostScript (.EPS, .PS)
- TrueType (.TTF)
- XML Paper Specification (.XPS)
suppose you have docx file but you don’t have Microsoft office installed with you then you can upload to Google doc and view it in your browser.
you can download it locally in browser and can save it hard disk also
More information can be found here.