Chapter 22

1. The façade pattern helps hide the inner implementation of an application and only exposing the necessary interface. This is particularly important when we are working with a large code base but our user only needs to interact with a small portion of our code.
2. When we need to make a change to an application, the abstraction that the façade pattern provides helps keep the client code separate and safe, which is useful in making the client side unaffected by pending software changes.
3. The operating system class works as a façade, hiding access to the different server classes from client code.