What you call people - changes how they fundamentally interact with you.
If you don't call them by anything - you loose connection with that person. If you call them by their name you start to form a connection.
But it can get more interesting when you give nicknames to that person.
You may call them an expert, a professional or a creative.
You may call them your college, your partner or your co-worker.
These may all mean the same thing but we must remember that different words mean different things to different people.
Be careful what you call someone: it can change how they act and how well you are connected to them.