1. A real object is something that is perceived as an entity and referred to by name; something perceptible by one or more of the senses; something intelligible or perceptible by the mind. A virtual object embodies the same concepts as real objects, but are created FROM concepts instead of giving rise TO them. 2. Freshman, Math Majors, and Commuters can be used as subclasses of the STUDENT class. 3. Transportation 4. A business class is a virtual class that reflects a class of objects (or concepts) in the real world. A utility class is a virtual class that serves the information system as a whole and, usually, does not reflect an object in the real world. So, the main difference is that a business class does reflect objects in the real world and a utility class does not. Some examples are: 5. The operation of a class is what it does or is capable of doing while its attributes are the properties, qualities, or characteristics that are associated with it. Attributes are mainly paired with values to define what an object or class IS while the operation is what it DOES. 6. It creates public and private areas, with the private attributes and operations being hidden and known only to the object itself. That is, how an object does something, and the data that it holds, are concealed within the same object, secure from abuse or misuse. 7. Simple inheritance is when an object inherits the behavior of a superclass, such as a tree inheriting the fact that it has a trunk. Multiple inheritance is when man made objects can have many parents, thus inheriting the behavior of many different parents. Such an example is a Swiss Army knife having a bunch of different unique functions. 8. Object oriented modeling is using an object-oriented approach to building conceptual and logical models of the system. Meanwhile, UML is a meta-modeling language, which means that UML models the models. 9. UML is mainly a language for object-oriented modeling. By that, it takes object-oriented concepts that object-oriented languages use, like classes, objects, etc. and represents it.