Final answer:
The difference implied is whether a person is in a prone or supine position, with prone being face-down and supine being face-up during massages or procedures.
Step-by-step explanation:
The major difference in body positioning referenced in the question relates to a person being in a supine or prone position during massages or medical procedures. When a person is prone, they are lying face-down. Conversely, when a person is in a supine position, they are lying on their back, face-up.
This information is pertinent in fields such as health sciences and physical therapy, where body positioning is crucial for certain treatments and assessments.