DIAGRAMS
图群
When you model something, you create a simplification of reality so that you can better understand the system you are developing. Using the UML, you build your models from basic building blocks, such as classes, interfaces, collaborations, components, nodes, dependencies, generalizations, and associations.
在你建模某些事物的时候，创建的是现实的简化版，以便你能更好地了解正开发的系统．使用
UML，你建立的是你的模型的基本构建块，如类群，接口群，交互群，组件群，节点群，依赖群，泛化群和关联群．
Diagrams are the means by which you view these building blocks. A diagram is a graphical presentation of a set of elements, most often rendered as a connected graph of vertices (things) and arcs (relationships). You use diagrams to visualize your system from different perspectives. Because no complex system can be understood in its entirety from only one perspective, the UML defines a number of diagrams so that you can focus on different aspects of your system independently.
图群是你认为这些构建块代表的含义．一个图是一组元素的图形描述，通常表现为顶点
(事物)
和弧线
(关系)的连通图．你使用图从不同的视角使你的系统可视化，因为没有复杂系统可以仅从一个角度了解它的全部，UML定义了大量的图，这样你就可以专注于你系统的不同独立面．
Good diagrams make the system you are developing understandable and approachable. Choosing the right set of diagrams to model your system forces you to ask the right questions about your system and helps to illuminate the implications of your decisions.
好的图群让你开发中的系统易于理解和易于接近
．
选择对的图集来建模你的系统，迫使你问关于你系统的正确问题和有助于阐明你所做决定的影响．