Common Craft is a great website that I have used countless times in class to explain a topic for the first time or review something that students have already learned. The videos on Common Craft are created using stop motion animation which is simple to follow and fun to watch. The premise of Common Craft is to create videos "in plain English" so that they are easy to understand. Check out the list of videos below (click to see larger image) as well as an example video on CFL light bulbs.
Head over to Common Craft and check out some of the videos that fit with your classroom curriculum. There are also some great videos that you can use to help yourself to better understand some of the new emerging technologies and websites.