Genetic interactions refer to the ways in which different genes influence each other's effects on an organism's traits. These interactions can occur through various mechanisms, such as epistasis, where one gene can mask or modify the expression of another gene. Understanding these interactions is crucial for studying complex traits and diseases, as they can help explain variations in phenotypes among individuals. In addition to epistasis, genetic interactions can also involve additive effects, where multiple genes contribute to a single trait. This means that the combined influence of several genes can lead to a more significant impact on characteristics like height or susceptibility to certain diseases. Researchers often use model organisms, such as fruit flies or mice, to explore these interactions in a controlled environment.