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QCObjects has special components called shadowed components. A shadowed component is a QC object definition that you can extend to allow the content of your component to be shadowed in the browser. Shadowed components define internal structure, scoped CSS, and encapsulates your implementation details. Lightning components are not the same thing that the same component that you're actually familiar with. They are completely independent. Lighting components are meant to restrict the global behaviour of the global components in some ways. The purpose of lighting components is to be absolutely available to be injected everywhere.