A Compact Shared Document file extension is a compressed assemblage of electronic document files that consist of text and images. As a CSD it compresses the original collection of files by a factor of ten. In Windows, the CSD file extension is a temporary file created by Microsoft Sharepoint Server.
PC and mobile devices support the general CSD file extension, which requires special software to decompress and open. The CSD file extension specific to the Windows operating system is a temporary file created during the Microsoft Sharepoint Server 2007 backup process. It is a remnant of a file that serves no important function.