Final answer:
Interphalangeal (IP) joints are the connections between the phalanx bones in the fingers and toes, allowing for movement such as bending. The metacarpophalangeal joints are a specific type found at the base of the fingers and thumb, facilitating various movements.
Step-by-step explanation:
The interphalangeal (IP) joints are articulations between adjacent phalanx bones of the hand or foot digits. These joints are found in the fingers and toes and allow for movements such as bending and straightening. The metacarpophalangeal joints, also known as the knuckle joints, are a specific type of these articulations located at the base of the fingers and thumb, where the metacarpal bones of the hand connect to the proximal phalanges. These joints are examples of condyloid joints, a type of biaxial joint, which permits flexion and extension, abduction and adduction, and circumduction movements.