TAD uses a powerful OOPs (Object Oriented Programming Systems) mechanisms that is found in many object-oriented computer languages. In fact, we would even say that, in some aspects, TAD has a much more clever mechanism than seen in many OOPs computer languages.

To learn about the deeper concepts of OOPs, there are many videos, documents on the Internet that goes in the why of OOPs. We will give some links here.

But let us explain:

When you place objects into a class, you usually would do so because you recognized some properties that were common for those objects. This is kind of what happens in a school classroom. Say the principal of a school wants to visually notice the students of various classes playing in the playground – so he orders different color school uniforms for each standard (grade) in the school. So the 1st Standard(grade) students would be dressed in Pink, the 2nd Standard(grade) students are dressed in blue, and so on.

Now the principal comes for inspection. Say, he comes to the class say of the 2nd standard would be surprised to see someone wearing pink there. Why? because the entire class of the 2nd standard students are supposed to be dressed in blue. Each student in the class need not be instructed separately.

On a similar analogy, you can set properties in TAD at the class level. Usually that is where properties are set. Unless you have some compelling reason to give a different property for some specific object/s in that class.

When you set a property for a class, then you can also instruct TAD whether that property value should get inherited to other sub-classes below that class. (This is where the school-classroom analogy may break, as a school class may not have a concept called a sub-class)

You should ALT-Double-Click the mouse cursor at the 2nd column in the Class property editor for it to toggle the inheritance.