For example, practically any object-oriented modeling language will need to define the concepts of classes, attributes, associations, interactions, and so on.

例如，实际上任何一个面向对象的建模语言都需要定义类，属性，关联，相互作用等概念。

youdao

A number of other general functions and constants are used to control the run of a simulation, but the important concepts are tied to the classes.

有许多其它常规函数和常量用于控制模拟的运行，但重要的概念都与这些类结合在一起。

youdao

Classes provide the structure for software concepts or entities, whereas objects are live instances of classes.

类提供软件概念和实体的结构，而对象是类的真实的实例。

youdao

But the group doesn't prescribe which concepts must be addressed, nor does it track the number of classes offered at member schools.

WSJ: Some B-Schools Step Up Efforts to Tie Ethics to Business Programs