Ratio or Fractional Scale: the ratio between a distance on a map and the actual distance on the ground – 1:62,500 (or 1/62,500) means that one unit (e.g., an inch) on the map equals 62,500 of the same units on the ground.

Graphic Scale: usually consists of a line  or bar subdivided into divisions corresponding to a mile or kilometer. This scale is easily visualized and stays in the same proportions in the map is enlarged or reduced.

Verbal Scale: used to discuss the map, but is rarely written on it.  Basically, it is the spoken ratio or graphic scale.