Hello, welcome to today's lesson! Today, we will uncover the principles of Revising Basic Design Patterns - Composition! Composition is a valuable component of software design patterns, enabling the creation of complex classes from simpler ones. Our focus today is on understanding the concept of composition, its importance in software development, and how to implement it effectively in Ruby.

Let's delve into the concept of Composition. In object-oriented programming (OOP), composition allows a class to include other classes, facilitating the development of sophisticated systems out of simpler components. For example, constructing a car involves combining various independent components like the engine, wheels, and seats — a real-life illustration of composition. It's important to note that in composition, if the parent object (the car) is destroyed, the child objects (the components) also cease to exist.

Now, let's transform theory into practice with a Ruby implementation of the composition pattern. We'll model the previously mentioned car scenario by creating a Car class in Ruby that incorporates objects from the Engine, Wheels, and Seats classes. These child objects exist within the Car class, forming its components.