Unified Modeling Language
Introduction:- Most design approaches have two aspects to them—a language or a notation to express the design, particularly while it is being developed, and a methodology for developing the design. As design is a creative and iterative activity, a good notation should aid the designer during the design activity. This means that the notation should allow the designer to succinctly capture the key aspects of the design, and allow easy communication to encourage brainstorming. With good notation, often the methodology for design becomes a set of general rules, and the notation becomes the primary tool for creating the design.
Unified Modeling Language (UML) is a graphical notation for expressing object oriented designs. It is called a modeling language and not a design notation as it allows representing various aspects of the system, not just the design that has to be implemented. For a design, a specification of the classes that exist in the system might suffice. However, while modeling, during the design process, the designer also tries to understand how the different classes are related and how they interact to provide the desired functionality. This aspect of modeling helps build designs that are more likely to satisfy all the requirements of the system. Due to the ability of UML to create different models, it has become an aid for understanding the system, designing the system, as well as a notation for representing design.