Is pharyngitis the doctor term of sore throat ? or is pharyngitis something different ?

Pharyngitis means: Inflammation of the pharynx, just like appendicitis means inflammation of the appendix or cholecystitis is inflammation of the gallbladder. "sore throat" is pretty general, and even as lay terminology could imply a viral pharyngitis or a strep bacterial pharyngitis. You could even have a mechanical pharyngitis from screaming at a sports event, for example. Hope this helps!