Volume measures how much space is inside a 3D object — how much it can hold. Measured in cubic units: cm³, m³.
Surface area measures the total area of all the outside faces — how much material you'd need to wrap it. Measured in square units: cm², m².
Think of a cardboard box: the surface area is all the cardboard used to make the box, the volume is how much stuff fits inside.
Remember
Volume = inside space (cubic units, ³). Surface area = outside faces (square units, ²). The unit tells you which one you're dealing with.
Real World
A drinks can: volume tells you how many millilitres of liquid it holds. Surface area tells you how much aluminium was needed to make it.
Feeling ready?
Put this concept to work with a practice workout.