Area is length times width and perimeter is 2 times length plus two times width. They are both used for measurments, although area focuses on the filling mass inside when perimiter is only the outer borders.
The perimeter is the distance around the outside of a shape. Perimeter is measured in units (e.g., cm). The area is the amount of space the inside of the shape takes up. Area is measured in square units (e.g., cm2).