Copy Sketch To Target dialog box

Copy Selected Sketch Into The Active File: Specifies that you want to copy the selected sketch into the active document.
Select One or More Target Files in the Assembly: Specifies that you want to copy the selected sketch into the files you select. You can specify the files you want by selecting them in the Assembly Tree View.
Assembly Tree View: Displays the tree structure of the active assembly.
Link to File: Specifies that the copied sketch is associatively linked to the parent sketch. When this option is set, if you modify the parent sketch, the child sketch updates.