As we continue our smart home system project, this unit will focus on two design patterns: the Command pattern and the Decorator pattern. These patterns will help us create a flexible and expandable system for automation and lighting control.

Let's briefly recap and see what we'll use in this unit.

Firstly, we'll utilize the Command pattern to implement a smart home automation system. This pattern will allow us to encapsulate a request as an object, thereby letting us parameterize clients with different requests, queue or log requests, and support undoable operations.

Secondly, we'll apply the Decorator pattern to enhance our smart home lighting system. This pattern will let us dynamically add additional functionality to the lighting system, such as changing colors, without altering the existing structure.

Let’s move to the practice section and start building our smart home automation and lighting system.