A format for storing video on CD-ROM. Known as XSVCD for short, eXtended Super VideoCD is an unofficial extension of the popular Super VideoCD format and uses the same codec (MPEG-2), but can use higher bitrates and resolutions to increase video quality. For instance, XSVCD can use PAL and NTSC resolutions instead of the standard CIF. Because it is not an officially recognised standard, compatibility with standalone DVD players is not universal.
VCDHelp - http://www.vcdhelp.com