CDR is the native format of the CorelDRAW software. The format is managed by the Corel Corporation and is not an open format. A number of large applications can handle the format, but the overall support is not great. The format specification is not stable: every version of CorelDRAW comes with a new version of the CDR format.
CDR files can be converted to the preferred SVG format via software such as Inkscape or Adobe Illustrator.
CDR is a non-preferred format for file type Images (vector).