A complementary good or service is something used or provided in combination with another good or service. The word complementary means combining to enhance or emphasize each other's qualities.

We all know that getting enough protein in our diet is beneficial to our health, but why is that? Proteins are found in every cell, tissue, and bodily fluid. It is an important component of our diet, ...

In his Pensees (“Thoughts”), Blaise Pascal wrote: “By space the universe encompasses and swallows me up like an atom.” In Leaves of Grass Walt Whitman wrote: “I contain multitudes.” On the surface, ...