Final answer:
Inferior (or caudal) describes a lower position than another part of the body, while lateral describes the side and medial describes the middle of the body.
Step-by-step explanation:
Inferior (or caudal) describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is inferior to the abdomen.
Lateral describes the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits.
Medial describes the middle or direction toward the middle of the body. The hallux is the medial toe.