Cargo containers are high-strength metal containers that are made in standard lengths of 40 feet and 20 feet. Other names for cargo containers include c-containers, sea containers, and shipping containers. The standard sizes of c-containers facilitate their movement easily from the truck to ship or rail.Cargo, also known as freight, refers to goods or produce being transported from one place to another – by water, air or land. Originally, the term “cargo” referred to goods being loaded onboard a vessel.Cargo originates from the Latin word carricare which means "to load on a cart, or wagon." Cargo can be loaded on a cart, but it's usually loaded on something much bigger. On a ship, cargo is stacked up in huge, colorful metal containers.