The thumb is one of the five digits on the human hand, located opposite the other four fingers. It is shorter and thicker than the fingers, allowing for a unique range of motion. The thumb plays a crucial role in grasping and manipulating objects, making it essential for tasks like writing and holding tools. Anatomically, the thumb consists of two bones called phalanges, connected by a joint that enables its wide range of movement. This joint, known as the carpometacarpal joint, allows the thumb to touch the tips of the other fingers, a motion known as opposition, which is vital for fine motor skills.