Hot cocoa is made with cocoa powder and milk. Hot chocolate is made with melted chocolate (milk, dark, and/or white), water or milk or cream and sometimes vanilla flavor. Cocoa is going to be sweet and lighter. Got chocolate is going to be less sweet but thicker and richer.
I’ll be sure to let you know. Unless we stumble on each other by one first. It’ll probably be the one in the ballroom. Better acoustics.