what's all this/that?
What's all that about?
What is the meaning or purpose of the topic being discussed? A: "Jeff is still really mad at Jen." B: "Yeah, what's all that about? I thought they were best friends." Cross-country skiing perplexes me. I can understand the appeal of regular skiing, but skiing uphill? What's all that about?
what's all this
What is the meaning behind this? Please explain why this is the case or if this is true. What's all this about the company laying off staff? I never approved anything like that! Tommy, what's all this I hear about you failing your science class?