A Weighted Value Range is one which accounts for different degrees of importance you may wish to apply to certain values. For example, when dealing with density, an Entity's experience of high density (say 2 person/square metre) may be much more important to you than the experience of 0.25 person/square metre). With a weighted value range, you can give this higher level of density a 'weight factor' which will be used when calculating a weighted Map.