A coupling (or a coupler) is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.
Cake is a form of bread or bread-like food. In its modern forms, it is typically a sweet bakeddessert. In its oldest forms, cakes were normally fried breads or , and normally had a disk shape. Determining whether a given food should be classified as bread, cake, or pastry can be difficult.
