Insects are a diverse group of organisms that belong to the class Insecta. They are characterized by their three-part body structure, which includes a head, thorax, and abdomen, as well as six legs and often wings. Insects play crucial roles in ecosystems, such as pollination and decomposition, making them vital for the health of our environment. With over a million described species, insects are the most numerous group of animals on Earth. They can be found in nearly every habitat, from forests to deserts. Some common examples include bees, butterflies, and ants, each contributing uniquely to their ecosystems.