This chapter has covered some pretty technical material and concepts. COM is not simple to understand, and it does take a bit of studying to really get a good hold on it. However, using COM is ten times easier than understanding it, as you'll see in the next chapter. Anyway, you also took a look at DirectX and all of its components. So once you've seen the details of each component and how to use it in the following chapters, you'll have a good idea of how they fit together.