Final answer:
The communication style that is private and occurs between close friends or family is the Intimate style. A casual style can be present in a relaxed work environment, but respectful behavior is always important.
Step-by-step explanation:
The type of communication style that is private and typically occurs between close friends or family members is known as the Intimate style. This style is characterized by personal, private, and informal communication. It's generally not used in professional settings. In contrast, the casual style of communication might be used among colleagues who are on friendly terms but still retain a level of professionalism. Even in work environments where a casual style is adopted and the dress code is relaxed, or you are encouraged to address the company president by their first name, it is important to remain observant of respectful behavior.