make systems more maintainable. E.g., rather than having IF-THEN statements that determine which subroutine or function to call, a developer can just send a message to the object and the object will select the appropriate code based on its type.

One of the first examples of how this can be used was in the domain of computer graphics. There are various complexities involved in manipulating graphic objects. For example, simply using the right formula to compute the area of an enclosed shape will vary depending on if the shape is a triangle,