What is point guard?

Do you want to try? This was Mark's question. Because I complained about his idea, which Yo become a point guard, he thought I wanted to become a point guard. Actually, I wanted to, but when he asked me this question, I did not answer clearly. Oh my god!! How did I do that?? What all I had to say is “Of course! I can handle!” but, for some reasons, I was afraid to say so. Now, I should make my mind firmly and tell Mark.