Divx / MPEG

[tatayet]

Hi there ... just a simple question to clarify ...

What is the difference between DIVX and MPEG ?

Is VIVX just a video codec that allows the MPEG1, MPEG2, MPEG3 or MPEG4 viedo compression ?
If yes, then what are some other examples of video codecs that can also be MPEG ?

Thanks !