Complements

Complements are pairs of items where the presence or use of one increases the value or usefulness of the other. For example, printers and ink cartridges are complements—having a printer without ink isn’t very helpful, and vice versa. In economics, complements are goods often consumed together, like coffee and sugar. When the price of one complement drops, the demand for the other often increases because they are used together. Essentially, complements work together to enhance each other's value or utility.