A frog is an amphibian known for its smooth, moist skin and long hind legs, which are adapted for jumping. Frogs belong to the order Anura, which includes over 7,000 species. They typically live in or near water, as they need a moist environment to survive and reproduce. Frogs undergo a life cycle that includes stages such as egg, tadpole, and adult. Tadpoles are aquatic and breathe through gills, while adult frogs breathe air through lungs. Frogs are also important to ecosystems, serving as both predators and prey, and they help control insect populations.