Surely any distinguished connoisseur of terminology gatekeeping such as yourself is able to distinguish between 'cc' and 'CC'. My terminal is able to spot the difference, you should be able to as well.

CC is an environment variable / internal variable used by most build tools to identify the current C compiler. cc is the standardized name of the executable, now usually an alias for gcc.

Both CC and cc refer to the C compiler, in slightly different ways.