Sexual dimorphism refers to the differences in physical characteristics between males and females of the same species. These differences can include size, color, shape, and the presence of specific features. For example, in many bird species, males may have brighter plumage than females, which helps attract mates. In mammals, such as lions, males are often larger and have manes, while females are smaller and lack this feature. This phenomenon is common in the animal kingdom and can also be observed in some plants. Sexual dimorphism can play a crucial role in reproduction and survival, influencing behaviors like mating rituals and territorial disputes. Understanding these differences helps scientists study evolution and ecological dynamics.