There is no sharp line between the various concepts and constructs in UML, but, for convenience, we divide them into several views. A view is simply a subset of UML modeling constructs that represents one aspect of a system. The division into different views is somewhat arbitrary, but we hope it is intuitive. One or two kinds of diagrams provide a visual notation for the concepts in each view. The views used in this book are not part of the UML specification, but we use them as an aid to organizing and presenting the UML concepts.
Table 1. UML Views and Diagrams
UML是用来描述各种各样软件模型的,它通过各种图形符号组成模型结构来描述系统的结构或静态特征以及行为或动态特征。它从不同的视角为系统建模,形成不同的视图(Views),每个视图代表完整系统描述中的一个抽象,显示这个系统中的一个特定的方面;每个视图由一组图(Diagram)构成,图中包含了强调系统中某一个方面的信息。