Rhinoceroses, commonly known as rhinos, are large, thick-skinned mammals native to Africa and Asia. They are characterized by one or two horns on their snouts, which are made of keratin, the same material as human hair and nails. Rhinos are herbivores, primarily feeding on grasses, leaves, and shrubs. There are five species of rhinos: the white rhinoceros, black rhinoceros, Indian rhinoceros, Javan rhinoceros, and Sumatran rhinoceros. These animals are known for their size and strength but are currently threatened by habitat loss and poaching for their horns, leading to conservation efforts to protect them.