Add-ons are like apps that you install to add features to Firefox. They let you compare prices, check weather, listen to music, and more. Let's give it a try. Click on the menu and choose Add-ons. Here I can browse or search for Add-ons. This one looks interesting, light beam. Let me click the Add to Firefox button to install it. Notice that it added a new button to the toolbar that I can use to open it. This is great, but I don't think I need to have access to this all the time. That's okay. Firefox is easy to customize so I can quickly move this to the menu where it's out of the way, but still easy to get to. There are thousands of add-ons available to add just the thing you need. Give them a try.