This UML Object Diagram Tutorial describes a class instance. It depicts a system's specific functionality. The class diagram differs from the object diagram in that the class diagram primarily represents a system's bird's eye view, also known as an abstract view. Classes define the behavior of objects, which are real-world entities. Objects are used to represent an object-oriented system's static view. An object cannot be determined without its class. Object and class diagrams are similar in some ways.
