The target audience for an Account job is a team within a larger organisation. For example, if a taxi company caters their services to a company, it can book a job to a specific department and bill the specific department.
The target audience for a Passenger job is a specific person who wants to use the taxi service to get from their pick-up location to their preferred destination.
The use of 'Account' or 'Passenger' jobs is mostly for preferred billing purposes.