What Is UML?
The Unified Modeling Language (UML) is an industry-standard notation for describing and analyzing object-oriented systems. UML is independent of the process that you use to design and build systems. Its main advantage is that with a standard notation, you can describe your system to a wide audience and obtain a consistent understanding.
UML consists of a set of diagrams that communicate a view of a system. For example, a class diagram describes objects within a system and their relationships to other objects. A use case diagram describes the functionality of a systemhow someone uses the system. An activity diagram describes the steps that are required to do something: complete a use case, deploy an application, or make broccoli and garlic penne, for example. Although UML has a rich set of diagrams, we will use only class diagrams for this discussion.