One of the best is the ability to search for specific documents based upon file types.
Perhaps you are looking for a Power Point (ppt or pptx) or an Adobe Acrobat file (pdf).
With Google, you can search for these files types, plus a whole lot more.
To do so, just type filetype:xxx search terms where xxx is the document type you are searching.
For example, to search for PDFs concerning Hillary Clinton, enter
filetype:pdf Hillary Clinton into Google:
Search result will return the desired documents.
Google indexes a number of common file types including:
- Adobe Portable Document Format (.pdf)
- Microsoft Excel (.xls, .xlsx)
- Microsoft PowerPoint (.ppt, .pptx)
- Microsoft Word (.doc, .docx)
- Rich Text Format (.rtf, .wri)
In addition, a number of technical and lesser-known file types are also indexed and searchable: