In computing, DOC or doc (an abbreviation of "document") is a filename extension for word processing documents, most commonly in the proprietary Microsoft Word Binary File Format. Historically, the extension was used for documentation in plain text, particularly of programs or computer hardware on a wide range of operating systems. During the 1980s, WordPerfect used DOC as the extension of their proprietary format. Later, in 1983, Microsoft chose to use the DOC extension for their proprietary Microsoft Word format. These uses for the extension have largely disappeared from the PC world.
Office Open XML (also informally known as OOXML or Microsoft Open XML) is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. The format was initially standardized by Ecma (as ECMA-376), and by the ISO and IEC (as ISO/IEC 29500) in later versions. Starting with Microsoft Office 2007, the Office Open XML file formats have become the default target file format of Microsoft Office. Microsoft Office 2010 provides read support for ECMA-376, read/write support for ISO/IEC 29500 Transitional, and read support for ISO/IEC 29500 Strict.Microsoft Office 2013 and Microsoft Office 2016 additionally support both reading and writing of ISO/IEC .