What is meant by configuration in an organic compound? What is meant by the reflection of a configuration?

(N/A) Configuration: The spatial arrangement of functional groups (atoms) around a carbon atom is called the spatial configuration of that carbon.
Below are two spatial structures of the same compound $CHClBrI$.
The arrangement of groups (atoms) attached to the carbon in structure $(A)$ and structure $(B)$ is not the same. These structures $(A)$ and $(B)$ are mirror images of each other,which is called the reflection of a configuration.
The reflection of $(A)$ is $(B)$ and the reflection of $(B)$ is $(A)$. The configuration of carbon in structure $(A)$ is the reflection of the configuration of carbon in structure $(B)$. If $(A)$ and $(B)$ are different,then the optical activity of $(A)$ and $(B)$ is opposite,and their chirality is also opposite.