Qual è la differenza tra questi ? (or tra di essi) Quali differenze ci sono? Che differenza corre fra questi? There is almost any difference if they are considered as vehicles (they transport many persons -since 15 to 60 I guess-), the difference is related to their function pullman : used to very long track (from city to city) autobus : used for short track (inside city) corriera : used for long track (from village to city and back) There is also "scuolabus" or "pulmino della scuola" : it is used by schools to take and bring back little students (of primary school) from and to home.