What is meant by unisexual and bisexual flowers?

Unisexual flowers are those that contain either male reproductive structures (stamens) or female reproductive structures (pistils), but not both. This means that a plant with unisexual flowers may produce either only male flowers or only female flowers. In contrast, bisexual flowers, also known as perfect flowers, contain both male and female reproductive organs, allowing them to potentially self-pollinate or cross-pollinate with other flowers. Examples include roses and lilies, which have both stamens and pistils in the same flower.