Computer Graphics Metafile (CGM) is free, platform-independent, international standard metafile format for storing and exchanging vector graphics (2D), raster graphics, and text. CGM uses an object-oriented approach and many function provisions for image production. CGM uses these object-oriented characteristics for remolding graphical elements to render an image. A metafile contains necessary information that defines other files. In CGM, a text-based source file contains all graphical elements that can be later compiled into a binary file.
ODT files are type of documents created with word processing applications that are based on OpenDocument Text File format. These are created with word processor applications such as free OpenOffice Writer and can hold content such as text, images, objects and styles. The ODT file is to Writer word processor what the DOCX is to Microsoft Word. Several applications including Google Docs and Google's web-based word processor included with Google Drive can open the ODT files for editing.
You can also convert CGM into many other file formats. Please see the complete list below.