What is the role of a complement in economics and how does it impact the demand for a particular good or service?

In economics, a complement is a good or service that is used together with another good or service. Complements have an inverse relationship with demand, meaning that an increase in the price or availability of one complement can lead to a decrease in the demand for the other complement. This is because consumers may be less willing to purchase one complement if the other is more expensive or less accessible.