Apple Watch activity summary

Can you tell me what total calories means? It is located below the red graph when I look at a daily summary on my Apple Watch Activity. Above the “move” graph it says I burned 707 calories. But below the graph it says total calories 2,023. Where does that number come from?

also, the graph beneath it , the exercise graph says I exercised 180 min. Then below the graph it says “total 15 hours”. What does that 15 hours mean?

thank you!!!!