The first step is to add your video tag. You can also add parameters for your video with height and width. You add the video by typing source src = "file name" and type = "file type".
The second step is to make sure that your file type is supported, and if it is not, you can add some code to make sure that it will play. You do this by adding the same orginal source code, but changing the file type in the "file name" part and the "file type" part.
