Beginner Question: What's is DTS?

[Afrinux]

Hi everyone!
I have started reading the MPEG-1 specifications. And I am a little puzzled with the time stamps:
1. PTS (Presentation Time Stamp) is the time at which a pack should be decoded.
2. SCR ( system clock reference ) is used to adjust STC( system time clock ).
First I thought that I had everything figured out until I ran into DTS and PTM.

What is the difference between PTS and DTS? When DTS is used?
What is the difference between PTS and PTM? For what purpose PTM is used.

Thanks for taking your time to read this.
If someone knows a good resource for beginners, please let me know or email it to me at afrinux at [gmail] dot-com.
Afrinux

[Fishman0919]

http://www.bretl.com/mpeghtml/DTS.HTM

http://www.chiariglione.org/mpeg/faq/mp2-sys/mp2-sys.htm#mp2-19

http://dvd.sourceforge.net/dvdinfo/pes-hdr.html

http://www.bretl.com/mpeghtml/conBR.HTM

http://fixounet.free.fr/avidemux/doc/en/bframe.xml.html

http://www.birds-eye.net/definition/d/dts-decode_time_stamp.shtml

Google.com is an amazing place

[dragongodz]

http://www.bretl.com/mpeghtml/MPEGindex.htm

EDIT:
DOH! Fishman0919 beat me while i was answering the phone. :)

[Afrinux]

Thank you guys!
http://www.bretl.com/mpeghtml seems to be an amazing place.
Google.com is an amazing place
Indeed, if you really know what you are looking for. I have spent 2 days looking for comprehensible tutorials using google search. But it was in vain.
Thanks again for taking your precious time to help me, I really appreciate it.
I hope one day, I will be helpful.
Afrinux

[Afrinux]

This will sound like a silly question:
What's the best way to learn MPEG1-2?

When I was beginning c programming, people told me that lots of exercices and reading someone's software were the keys. I did as so and I know I have realized how important those advices were.
Thanks in advance.
Afrinux