Final answer:
The method of tapping the body to ascertain characteristics of underlying organs is percussion, which is distinct from palpation, auscultation, and inspection.
Step-by-step explanation:
The method that uses fingers to tap the body lightly or sharply to determine the density, size, and position of underlying organs is known as percussion. This technique is an essential part of the physical examination and can provide valuable information about organs such as the liver, lungs, and intestines. On the other hand, palpation involves using the hands to feel the body's internal organs, auscultation involves listening to the sounds made by the internal organs, typically with a stethoscope, and inspection requires visually examining the patient for signs of disease.