The statement "1 cm represents 2 m" means that 2 meters of a actual figure is represent by 2 centimeters on a plane or something like it.
Scales are pretty important and are highly used in architecture, there, we use scales to represent real big areas as planes, where we measure each part of the are in a smaller representation. So, that's what means the given scale, it means that each actual 2 meters is equivalen to 2 centimeters on a smaller representation.
