Axis mapping, also called a two-by-two matrix or opportunity map, plots ideas, users, products, or design directions against two axes representing the dimensions that matter most to the design challenge. The resulting map creates an instant visual of the design space, revealing clusters, gaps, and outliers that cannot be seen when ideas sit in a list. It is one of the most versatile and frequently used tools in a designer's analytical and ideation toolkit precisely because of its elegant simplicity.