A cone is a circle that's been pulled to a single point. Ice-cream cones, party hats, traffic markers and rocket nose-cones all share this shape.
Volume
V = ⅓ π r² h
Exactly one-third of the cylinder it'd fit inside.
Surface area
A = π r² + π r ℓ
ℓ is the slant height (from apex to edge of base).
Try this: fill a cone with water and pour it into a cylinder of the same base and height. It takes exactly three cones to fill the cylinder.