How do i make one of my video files become a dvd?

okay, i i have this seminar about school shootings coming up. i saved a video i found on youtube into "my videos" on my computer. so now i need to get this video onto a dvd so i can play it in a dvd player for my seminar. i don't know if what i am asking for is to burn it or convert it.... i really don't know the difference. as long as i can play it in a DVD player im happy.