VCD is a format that has been around for a while now. It is mainly used in the Asian countries such as China, Indonesia etc. They are region and parental free and they can be played on your PC using windows media player of quicktime movie player.
It involves the use of MPEG 1 compression for the video and MP2 compressin for the Audio.
It uses a CBR for video at 1150kb second. CBR stands for Constant Bitrate meaning that the bitrate for video is fixed and doesn't change during the movie.
The Audio for a standard complient VCD is 224k/bit per second.
The quality is the equivalent of VHS but it has one advantage.
That is that playback quality will be the same all the time unlike VHS which decrease everytime you play it.
Most good quality DVD standalone players suppot this format.
VCD is a internationally recognised format just like CD and DVD.

Standard Compleint VCD Consists of

352 x 288 (PAL)
352 x 240 (NTSC)
MPEG 1 Video Compression at 1150 k/bits with a CBR
MP2 Audio compression at 224 k/bits Stereo or Joint-Stereo