Believe it or not, unless you’ve used a fire extinguisher before, there is a good chance you’ll use one when it counts. When there is an active fire, you will be under pressure, and that is not the time to open up a YouTube video to figure it out. 
While it seems like a point-and-shoot method should work, there are a few things you need to know. This brief video from the City of Fayetteville, NC, walks you through the things you need to know.