A range field is a computed picklist field associated with a numeric field: range limits and the associated field are stored in the computation expression and the range category name and icon are stored in the database as picklist items. When a value is entered in the associated numeric field, the appropriate range category displays in the range field. Range fields are useful for defining thresholds for numeric data and providing a broad overview of that data. For example, if a Project type has an integer field called Critical Defects that displays the number of Defect items marked Critical, you could add a range field called Defect Status that displays one of the following range categories based on the number of items in the Critical Defects field:

You can also add visual indicators to a range field by using customized images for each range category or by using the item presentation template designer to render range fields differently for each range category. For example, in the Defect Status field you could render Golden as black text on a white background, Acceptable as blue text on a white background, Watch as black text on a yellow background, and Trouble as red text on a yellow background.