Shipping containers at the Port Newark-Elizabeth Marine Terminal in New Jersey, USA

A container-freight train on the West Coast Main Line near Nuneaton, England

A container ship being loaded by a crane in Copenhagen Harbour

Hauling a container by road

Containerization is a system of freight transport based on a range of steel containers ("shipping containers", "ISO containers" etc.). Containers are built to standardized sizes. They can be loaded and unloaded, stacked, transported over long distances. They can be transferred from one mode of transport to another—ships, rail and semi-trailer trucks—without being opened. The system developed after World War II. It led to greatly reduced transport costs, and supported a great increase in international trade.