The OSI model has stood the test of time. It's used to describe the functionality of various networking appliances and the logical protocols that interact on the physical media. Modeling is important because it provides a way for experts to talk about what's happening in the abstract. Think about something you use every day that you could describe using a model. For example, a bicycle. What are the common parts shared by all the different kinds of bikes? How can you use the parts to describe the differences between the operation of one bike and another? Enjoy this discussion topic and apply what you are learning this week to your model.