爪 (zhǎo) refers to the claws or nails found on the fingers and toes of humans and many animals. In humans, nails are made of a hard protein called keratin and serve to protect the sensitive tips of fingers and toes. They also play a role in gripping and manipulating objects. In animals,爪 can refer to the sharp, curved claws used for hunting, climbing, or defense. For example, 猫 (cats) have retractable爪 that help them catch prey, while 鸟 (birds) use爪 for perching and grasping.爪 are essential for various survival functions across species.