Sometimes there are features for SketchUp that we want to test with the community before it it's ready to be fully released. You might call these "Optional Features" or a sneak peak into the future of SketchUp, but you can also look at a chance to help shape it as well. These Labs features are something more than a beta test. To start, we have Live Components which are similar to Dynamic Components, but also different. Right now you can work with some components created by us, but we'll be bringing the ability to create your own soon enough as well.