class and runtime

[DeaD_EyE]

can explain this statement? what is the importance of the creation of a class in runtime? how can a class be modified after creation?

This is not possible with static compiled languages. During the compilation, the compiler needs to know exactly all data types.
A dynamic language allows creation of objects during runtime. In Python, classes are also objects.

This allows to create or change behavior of classes (types), but not everything which is possible, is done.