What size containers do ships use?

Ships primarily use standardized shipping containers, with the most common sizes being 20-foot and 40-foot containers. The 20-foot container has a capacity of about 33 cubic meters, while the 40-foot container offers approximately 67 cubic meters. There are also variations like the 40-foot high cube container, which provides additional height for taller cargo. These standardized sizes facilitate efficient stacking, loading, and unloading during transportation.