A DVD is a standard definition, software based media that has very specific format specifications.
There is always a VIDEO_TS folder and usually, but not necessary AUDIO_TS folder. Inside these folders the MPEG2 files, that are always 720x480 NTSC/720x576 PAL, are encoded into a series of VOB files of no more than 1 gig each.
Authoring a DVD is a specific and universal way that all DVD's are playable without funky formats, etc. For High Definition, the only currently existing format that is universal is now BLU RAY from Sony.
If you are just burning the files onto a DVD, it is very unlikely there is a player that can play that back.