VCD 

This format is basically a CD containing digital video and audio files in MPEG-1 format (video playback quality is better than VHS but not as good as MPEG-2).

The average CD has a 650MB storage capacity (meaning you can store around 1 hour worth of MPEG-1 video). VCDs can be played back CD-ROMs and most DVD players. A CD-R/RW drive is required for outputting movies onto VCD. The quality depends on the content of the picture.

If there are many details (like in a street scene) or fast movements the data compression affects the quality. You then have an effect like in JPEGs with higher compression.