Designed as a protocol droid, C-3PO's main programming function is to interact with human society. He is an interpreter fluent in over six million galactc languages, specializing in the areas of etiquette and translation--especially important during diplomatic missions. To aid in these tasks, he is equipped with microwave and olfactory sensors, photoreceptors, vocabulator speech units, energy transducers and broad-band antenna receivers. He was programmed with an elegant, human-sounding voice, but more often then not C-3PO is heard whining and bickering with his companion, the astromech droid R2-D2.
