Self-storage facilities are dedicated spaces for the storage of personal or business items.
Container storage is very much the opposite.
It got its name because the early sites were literally fields filled with shipping containers of all shapes and sizes, which people could pay to rent and store in.
A huge problem in a container is damp, As temperatures change the air inside the container creates moisture on the ceiling which then drips down onto the customers items damaging them many insurance companies will not cover the goods in a container.
Container storage tends to work best for people who are storing a lot of large outdoor items which won't get damaged by the damp.conditions.