An intermodal container (also container, freight container, ISO container, shipping container or simply 'box') is a standardised reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerised intermodal freight transport system.
'Intermodal' indicates that the container can be moved from one mode of transport to another (from ship, to rail, to truck) without unloading and reloading the contents of the container.
Lengths of such containers, which each have a unique ISO 6346 reporting mark, vary from 8 feet (2.438 m) to 56 feet (17.07 m) and heights from 8 feet (2.438 m) to 9 feet 6 inches (2.9 m).
There are approximately 17 million intermodal containers in the world of varying types to suit different cargoes.
For air freight the alternative and lighter IATA-defined Unit Load Device is used.
Non-container methods of transport include bulk cargo, break bulk cargo and tank cars, tank trucks or oil tankers used for liquids or gases.