A DOC file is a Word processing document created by Microsoft Word, a word processor included with all versions of Microsoft Office. It may contain formatted text, images, tables, graphs, charts, page formatting, and print settings.
The DOC file was designated as Microsoft Word's primary format in 1983. However, DOC files created by Microsoft Word 97 to 2003 versions differ from from DOC files created by Word 97 and earlier. In 2006, the .DOCX file replaced the DOC file with the release of Microsoft Word 2007. The DOCX file stores documents in the OpenXML format.
Common DOC Filenames:
Document1.doc - The default filename that Microsoft Word gives to new documents prior to Word 2007 (Word 2007 uses Document1.docx by default).