Unified Modeling Language is a standard that models application and business structures, processes and data. This standard helps design large and complex software programs before the code is created. UML allows users to visualize the big picture without worrying about the many small details required while programming.
UML is a standard created by the not-for-profit technology standards consortium Object Management Group Inc. The standard includes 13 different diagram types separated into three categories: structure, behavior and interaction. These include the object, package, use-case, activity, sequence and communication diagrams.
UML 2.0 includes several features not found in the first version. Nested classifiers allow diagrams to nest classes within their managing components. This feature also allows designers to add behaviors into classes and components. UML 2.0 also expanded on behavior modeling by requiring programmers to define behaviors
Before determining which development tool to create UML diagrams, a user should first decide on the methodology to use. Object-modeling technique, the Booch method and Objectory are a few commonly used methodologies. Afterwards, the user should pick a UML development tool that works best with the chosen methodology. Free tools, such as Visual Paradym, and paid tools, such as Microsoft Visio, MagicWorks and Visual Paradym, are a few options.