Very often we have a scale of values that can be generalized and described as a real number within the range of 0 and 1, 0 being the lowest value and 1 being the highest. For example if we are building an airplane with highest possible altitude of 5 miles we can represent the current altitude with a number from 0 to 1, in this case 0 will represent the plane on the ground and 1 on it’s highest altitude of 5 miles. This may be useful in many different situations, for example if you show this value to a person or instrument that is not familiar with the specific value but can understand the idea of minimum and maximum of this value. Another useful scenario would be in you want to represent this value in a diagram, arranging it from 0 to 1 makes it easy to plot on a surface of any size.