You choose the person. I tell you who they really are.
You choose who is X and who is Y. I tell you how they feel about one another.
You choose the parameters. Can be one person, a couple, or even a group.
Comprehensive answer to a simple question.
When you just want to know why.
You pick the subject. Person, place, event or thing. I look at it and tell you what I see.
You on the left, them on the right. How you fit together.
You ask a question. I make up a spread. If you like it, I read.
For problems. What caused them, what happened, and what happens next.