Container ships first began operating in 1951 and today approximately 90% of worldwide cargo is transported by container ships. Containers allow for efficient loading and unloading of standardized container sizes onto ships, trains, planes and trucks. The introduction of containers vastly improved port efficiency and reduced costs, boosting global trade. The largest container ship is Emma Maersk, which can carry 15,200 containers and measures 397 meters long and 56 meters wide.