What is the key difference between a manicure and a pedicure treatment?

The key difference would have to be that a manicure is when your hands are being treated by soaking, filing, and/or grooming and painting your nails, and a pedicure is when your feet are being treated by soaking, filing, grooming, and/or painting toenails. As for the difference within the meanings of "manicure" and "pedicure", the Word manicure came from the latin Word manus, meaning "hand", and the Word pedicure came from the latin Word pedis, meaning "feet".