In what two ways are mammals different from other vertebrates?

Mammals are distinct from other vertebrates primarily in their ability to produce milk through mammary glands to nourish their young, a feature unique to this class. Additionally, mammals typically possess hair or fur on their bodies, which aids in insulation and temperature regulation, setting them apart from other vertebrates like reptiles and fish that have scales or bare skin. These adaptations contribute to their diverse habitats and lifestyles.