I'm learning how to program and I want to know how to download a video from a web page. I don't want to use software to do it for me, I want to make it myself. I was thinking that I could get the video element's ID and then download it, but I'm stuck as I don't know much about HTML or web design.
This is not really related to ubuntu. And what you are asking for is for the most part not as easy. Now days most of the video sites around uses flashplayers. This hides the real location of the video from the user. To find out the real location you could try to download the flashplayer from the site and try to figure out how to get a direct link to the video. It requires some knowledge and I think you're better of using an already existing software.