While both can be used for shipping, a crate is different from a box. A crate has a frame while a box generally does not. Crates are rigid containers built for the purpose of protecting the contents. Crates can be made of wood, plastic, metal or other materials. Crates usually need to be designed to exactly fit what it is they are protecting. Reusing a crate that does not fit the contents can waste space and harm the contents. 