How does the presence of substitutes and complements affect market equilibrium in terms of elasticity?

In economics, substitutes and complements are important concepts that affect how much people buy and sell products. Substitutes are products that can replace each other, like butter and margarine. If the price of butter goes up, people might buy more margarine instead, which shows that the demand for margarine is elastic because it changes a lot with price changes. On the other hand, complements are products that are used together, like coffee and sugar. If the price of coffee rises, people will buy less coffee and, as a result, also buy less sugar, demonstrating that the demand for sugar is less elastic because it depends on the demand for coffee.