Relations between classes
An object model is a set of related objects. The number of relations can be many, but there are a few relationship types that can exist between two objects. Generally, there are two categories of relationships found between objects (or their corresponding classes): to-have relationships and to-be relationships.
We'll explore to-have relationships in depth in this chapter, and we'll cover to-be relationships in the next chapter. In addition, we will also see how the relationships between various objects can lead to relationships between their corresponding classes. Before dealing with that, we need to be able to distinguish between a class and an object.