A symbol is a resource identifier that consists of a text string (name) mapped to an integer value. Symbols provide a descriptive way of referring to resources and user-interface objects, both in your source code and while you’re working with them in the resource editors.
When you create a new resource or resource object, the resource editors provide a default name for the resource (for example, IDC_RADIO1) and assign a value to it. The name-plus-value definition is stored in the Resource.h file.
Note When you are copying resources or resource objects from one .rc file to another, the transferred resource’s symbol value, or symbol name and value, might be changed to avoid conflicts with symbol names or values in the existing file.