That depends on the DVD player. Some (especially more recent blu-ray players) will take a simple data-disk burned by your OS with a mp4 file on it. If you have an older (non-bluray) disk, you'll have to use a DVD authoring application to create video DVDs. This is not trivial and can't be done without special software. Also, in that case, the maximum resolution you'll get is 720x480 (north america) or 720x576 (Europe). This is really low resolution and won't look very good. If you're presenting on any recent HDTV, best thing is to see if it has a USB port on it and simply put a 1080p H264 export from Lightroom on a stick and plug it in. Most current TVs will play these. Most current Blu-ray players also have a USB port that you can do the same thing with.