Perimeter is the distance around a figure. The instances where we need to find perimeter include
1) The total length of the boundary of a marked field. This would involve adding the distance around it. Both the curved and straight paths
2) The length of barbed wire to be placed on a fence would require us to find the distance round the fence
The area of a shape is the space enclosed within the perimeter of the shape. The instances where we need to find area include
1) The area of a wall is calculated to determine how much paint is needed to paint it. The paint is used per square unit.
2) The area of a field is calculated to determine the cost of mowing it since the cost is calculated per unit square