Not only does the carton have to be moved a long distance, but its contents must be imported or exported according to the laws of both nations. The most common type of international shipping would be package delivery services that pick up at your office and deliver in another nation. This works like domestic shipping with added delivery time and customs declarations. You hand over the box and away it goes.
More complex shipments require a more complex shipping route, by land, sea, air or water.
To navigate through that obstacle course, freight-forwarders may be a great help. If regularly exporting, they may be a necessity. Forwarders can help prepare paperwork, fees, logistics and shipping routes for your goods. Try to find one with expertise is the country you are trading with. Any shipment going overseas muck be packed carefully and labeled legibly.