(1) (Computer Graphics Metafile) An ISO/IEC standard format for 2D graphics images introduced in 1987. Primarily a vector graphics format for technical illustrations and geophysical visualizations, CGM also supports raster graphics and text. As a metafile, it enables instructions to be included with the data to render any type of graphical element. Earlier GDM and VDM formats were merged into CGM.

The Web Version (WebCGM)
Because there were non-standard varieties of CGM in use, WebCGM was created in 1999 by the W3C and CGM Open Consortium to standardize the format for Web interoperability along with hyperlinking capabilities. In 2007, WebCGM Version 2.0 added programmatic access to elements via a DOM specification and an XML-based Companion File (XCF) format for non-graphical meta-data.

(2) (Consumer-Generated Media) The comments, opinions and product ratings from the general public that are posted on blogs, Usenet newsgroups and other Internet discussion boards.