The term "crate" derives from Latin, where its original meaning was a term for baskets.
Today a crate is defined as a shipping container that is often made of wood and is used to transport heavy or large items. Steel and aluminum crates are used in some scenarios, but are less common because of their excessive weight.
C.A. Plaskett was well known for conducting extensive wood crate testing and other types of testing when defining various components of transport packaging. He was also credited for documenting small wooden crate usage for the first time in the United States in 1930.
In his writing he states that crates had been in use before this documented time. He defined a wooden crate as a self-supporting structure in which all six of its sides must be put in place to result the rated overall strength of the container. Wooden crates are also distinct from wooden boxes. The difference is that strength of a wooden box is based on the weight it can carry before the top is installed. With a wooden crate it is rated with the top in place.
Both a large and a small wooden crate can be made from plastic, metal, wood or other materials. When people use the word crate it often implies a large or strong container. Plastic crates are usually smaller and in most cases are considered to be a container. When a crate is made of metal it is often considered an open crate or a cage.