A format for storing video on CD-ROM. Known as XVCD for short, eXtended VideoCD is an unofficial extension of the popular VideoCD format and uses the same codec (MPEG-1), but can use higher bitrates and resolutions to increase video quality. For instance, XVCD 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