A hob is a term used in Pennsylvania Dutch Country to describe a cast iron griddle. A remnant of the Victorian era, the hob originally kept beds warm during cold winters, but to the present day serves as a metal pad that provides additional insulation for casserole dishes.
In the United Kingdom, Singapore, and other parts of the commonwealth, a hob is another name for what people in the United States would call a stove or range. The cooktop of a hob may have gas or electric elements.