of static structure diagram that describes the structure of a system by showing the system's classes, their attributes and the relationships between the classes. Classifier - a category of UML elements that have some common features, such as attributes or methods. Client - Collaboration - A collaboration is a society of classes, interfaces and other elements that work together to provide some cooperative behavior that is bigger than the sum of its parts. Communication diagram Component - A component represents a software module (source code, binary code, executable, DLL, etc.) with a well-defined interface. The interface of a component is represented by one or several interface elements that the component provides. Components are used to show compiler and run-time dependencies, as well as interface and calling dependencies among software modules. They also show which components implement a specific class. Component diagram Composite structure diagram Composition - a specific type of relationship describing how one Object is composed of another Object; a form of Aggregation where the child object is destroyed if the parent object is destroyed. Condition - Connection - Constraint - natural language, programming language or Object Constraint Language boolean condition which may not be false if a Class is to be considered valid Containment - containment by value and containment by reference. Containment by value implies that an object contains another object; containment by reference implies that an object contains a pointer to another object. D Decision - a point in an Activity diagram where a Flow splits into several, mutually exclusive, Guarded flows. A Merge marks the end of the optional behaviour started by the Decision Dependency - a dependency exists between two defined elements if a change to the definition of one would result in a change to the other. In UML this is indicated by a line pointing from the dependent to the independent element. Deployment diagram Derived property - a property that can be calculated or inferred from other properties Diagram - a visual representation of a subset of features of a UML Model Directed relationship - Domain - a logical grouping that explicitly declares a rule which defines ownership of objects based upon some type or property. E Edge - a synonym for Flow Encapsulation - a means to bind together code and the data it uses. It is the basis of object oriented programming. Entity - Enumeration - a set of constant