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.
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.
