A slider dialog is a dialog that is used to set an editor option from a subrange of values by adjusting a horizontal slider. For an example of a slider dialog see figure 2.8.
The current zoom percentage is always visible in the bottom-right corner of the main window and is updated by the zoom commands. The zoom percentage is the ratio between the TCM coordinates and the X Window coordinates, which is 100% when there is no zooming. By zooming in, you make this percentage bigger, by zooming out, smaller. The zoom factor is the factor by which the zoom percentage is increased or decreased during zooming in respectively zooming out. The zoom percentage and factor are settings of the editor not of the document. So when a document is saved to file, the zoom percentage and factor are not stored. But when the drawing is saved as PostScript or as EPSF, the output is scaled by the zoom percentage.