<human>:  How does post office shipping work?
<bot>: Post office shipping works by sending a package through the postal service using a variety of shipping methods. The postal service can deliver the package using different methods such as First Class Mail, Priority Mail, and Express Mail, depending on how quickly you need the item to arrive. You can ship your package by visiting your local post office, through their website, or using a third-party service. Once your package is shipped, the postal service will provide you with a tracking number that you can use to monitor the status of your shipment.