[FFmpeg-user] Queries regarding MPEGTS/MPEG/MPG

[hello...]

Hello Everyone,
    I'm fairly new to the concepts of video formats. So, pls bear with me,
if the queries are too basic!! :)
    I want to convert the MPEGTS file using ffmpeg to avi format. Using
ffmpeg, I have done that without any issues.
    But I want to explore a little more into these formats. I have got some
basic doubts while going through the internet on video formats.
    Kindly take some of your time to clarify these. (I've already searched
enough using google!!)
    1. Where can I get the specification document for MPEGTS. (I've browsed
the official site of MPEG (*mpeg*.chiariglione.org/), but could not locate
it. To admit, I found the site a little confusing in the first attempt :()
    2. I used ffprobe to find the stream info of a ts file. But, can I use
FFmpeg to get the header details of a MPEGTS file? (I had earlier used one
tool, which parses the avi file, and gives the header values and
video/audio data in a good readable format. Expecting similar one for
MPEGTS format :))
    3. Finally, I see there are MPEG and MPG formats. Are these both same?
If not, what is the basic differnces between these two formats? In the
FFmpeg code, I could locate files for decoding MPEG, but not MPG. (It would
be helpful, if someone can give me the pointers towards specification docs
of these also)

   Once again, I request you to pls bear with me, if the queries are too
basic :)
   Thanks in Advance!!

Regards,
Sachin