Hard-shell turtles, also known as tortoises, are reptiles characterized by their protective, bony shells. These shells are made up of two parts: the upper shell, called the carapace, and the lower shell, known as the plastron. Hard-shell turtles are primarily terrestrial and can be found in various habitats, including forests, deserts, and grasslands. These turtles are herbivorous, feeding mainly on plants, fruits, and vegetables. They have a slow metabolism and can live for several decades, with some species reaching over 100 years of age. Hard-shell turtles play an essential role in their ecosystems by helping to maintain plant diversity and soil health.