odg ODG is a file extension for the OpenDocument (ODF) file format which is an XML-based file format. The OpenDocument file format is used in the creation of charts, spreadsheets, presentations and in word processing applications. XML is simply known as Extensible Markup Language which means, marking up data and encoding it into a file which is readable by both humans and machines.
The ODG file extension is used in graphics and stores vector graphics in standardized XML. It was first developed by the OASIS (Organization For The Advancement Of Structured Information Standards) and is meant to be used in other OpenOffice documents for storing texts, charts, spreadsheets and various graphical elements. When it was first created, the extension was used as a specification in the Apache OpenOffice suite, being one of the first office suites to offer and support the use of ODG files.