What is the difference between a courier and a postal service?

Question

Accepted Answer

Postal services are generally operated by a national government authority and are able to deliver to a country’s P.O. box network. The quality of service provided by a postal service varies by country. Courier services are private or public companies that may specialize in a type or range of services (E.g. various transit time options). Courier services do not have access to P.O. boxes owned by postal carriers and generally cost more than a postal service.