Why specify methods to resolve label conflicts?
When Maplex for ArcGIS is placing labels, there will always be competition for space. Setting conflict resolution specifications allows you to optimally use the available space for labels to be placed in.
Space can be controlled by setting feature weights and allowing labels to be placed over features if necessary, setting a label as a background and always allowing other labels to be placed over the top of it, removing duplicates of labels within a specified radius, and setting a buffer around labels. When a label must be placed on the map, the Never remove option can be selected, and the label will be placed regardless of space available, potentially resulting in overlapping labels.