Surface area is the total area that the surface of a three-dimensional object occupies. It is measured in square units, such as square meters or square centimeters. Different shapes have different formulas to calculate their surface area. For example, the surface area of a cube can be found using the formula 6a^2, where a is the length of one side. Understanding surface area is important in various fields, including architecture, engineering, and biology. It helps in determining how much material is needed to cover an object, such as paint for a wall or wrapping for a gift.