"In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects. ...
The class diagram is the main building block of object oriented modelling. It is used both for general conceptual modelling of the systematics of the application, and for detailed modelling translating the models into programming code. Class diagrams can also be used for data modeling. The classes in a class diagram represent both the main objects, interactions in the application and the classes to be programmed." [Class diagram. Wikipedia]
The template "UML class diagram" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.