In Revit we need to be able to edit lines to give the sence of depth, especially in an elevation. The Linework Tool allows us to do that. The Linework tool does not create new model or detail lines in the view. Instead, it overrides the current line style of the selected line and applies a different line style.
You can use the Linework tool to change the line style of Projection edges of model elements, including silhouette edges and projection edges caused by plan regions