Step 1. use a "video" tag

Step 2. set width and height

Step 3. set a source video

Step 4. set properties (i.e boolean attributes, preload values, etc)

Or....

Step 1: find the video you want to use on a hosting service such as youtube

Step 2: Copy the code in the embed options tab

Step 3: Paste it into your website

EXAMPLE:

(video is not mine)