What is MPEG?

My friends always ask me what do I do, and the answer is "I am working on audio visual engineering / support". "Oh, are you repairing VCR/TV/DVD or etc?" My friend asked.
I am not trying to explain what I do here, but I will write down some notes, especially on audio, video, and display technologies, and then you will understand what do I do.

Today I am going to tell you what is MPEG. If you type MPEG in yahoo search, I think you will get something like: MPEG (Motion Picture Experts Group). I have no plan to explain this in details, as all of your will fall asleep immediately, and instead I will use more real life example to explain this.

MPEG is an audio and video encoding standard. We have MPEG1, MPEG2, MPEG3 and MPEG4. Except MPEG3, all the others canbe found commonly in our daily life.
MPEG1. MPEG1 can be found on our VCD. The resoultion of MPEG is 352 x 240 pixel, and the frame rate is 30 frame per second (fps). The quality of the picture is quite close to our traditional VHS tape. Usually a standard 700Mb CD disc can carry 70 mins of video and audio.
MPEG1-Layer3, more commonly known as MP3. This is actually the audio component of MPEG1.
MPEG2. MPEG2 can be found on our DVD. The resoultion of MPEG2 is 704 x 480, and it was created for the needs of HDTV.
MPEG3. MPEG3 appearred only on the market shortly before it was replaced by MPEG4.
MPEG4. MPEG4 is targeted for mobile media player or web streaming. It has very high compession rate and requires lesser bandwidth. Usually the data rate for MPEG4 is lower than 64kbps and hence it is the ideal format for web video and audio streaming.