An analog clock is a clock or watch that has moving hands and (usually) hours marked from 1 to 12 to show the time. The clock face is circular and the hands move in a circular motion around the clock face. The longest hand indicates the seconds, the longer one indicates the minutes, and the smallest one indicates the hours. Analog clocks are different from digital clocks, which simply show numbers to denote the time. Some analog clocks have Roman numerals (I, II, III, etc) instead of numbers, or no numbers at all. Analog clocks are used to teach children how to tell time in Key Stage 1.