Why doesn't my DVD work on normal DVD players?

What is the difference of DVD movies i buy from the store and the DVD-r's i burn for myself that seldom work?

• I keep trying to make this simple dvd from a short file. Basically i want this 30 second clip to loop forever in a dvd player. I burn the dvd using windows dvd maker and it doesnt work on any dvd player, then i use nero and it only works in some dvd players. Why dont they work like the ones i buy at the store that work in every dvd player?

• Answer:

  The ones you buy at the store are DVD-ROMs The one you make yourself are using DVD-R or DVD+R. On a modern DVD player they both should work just fine so you obviously don't know how to make one. Things to remember a) ALWAYS finalize your disc b) Record using the DVD-Video format (NO -VR) c) Create a DVD-Video disc NOT DVD data disc d) Avoid using -RW or +RW (re-writables) 30 sec maybe too short. You may want to copy it 4-6 times and make a 2 min video, otherwise you will wear out the drive mechanism.