The column-fill CSS property controls how contents are partitioned into columns. Contents are either balanced, which means that contents in all columns will have the same height or, when using auto, just take up the room the content needs.
In multi-column layouts, the column-rule CSS property specifies a straight line, or "rule", to be drawn between each column. It is a convenient shorthand to avoid setting each of the individual column-rule-* properties separately : column-rule-width, column-rule-style and column-rule-color.