A fence to around a flower garden ---> perimeter
A box big enough to hold a computer ---> volume
Enough carpet to cover the floor ---> area
What is perimeter?
Distance around the outside of a shape.
What is volume?
The number of cubic units that make up a solid figure; the amount of space the figure occupies. In Cubic Units, or units³.
What is area?
The space or surface enclosed in 2-dimensional shape.
Using these definitions, it can be said that the fence acts as a perimeter surrounding a flower garden. Each side has a length.
A box big enough enough to hold a computer is the amount of space in the box to make it big enough to hold the computer (The volume of the box).
The amount of carpet to cover the floor is acting as a 2-dimensional shape scenario as the carpet is likely a standard typical shape such as a rectangle or square. Overall, enough to occupy a standard-sized room.