Main Tab - Glyph Separation
The straight horizontal lines in the graph represent natal planets that are stationary. The wavy lines are planets that are moving and where they moved over the course of the Graphs period and the lines intersection between natal and transiting planets represent exact aspects or conjunctions. The edges of the graph, particularly on the left and right sides can have collision problems where the glyphs can overwrite each other if they were too close in the natal chart. The lines are drawn in their actual locations be the glyphs are labels showing what planet that is. These lines are drawn in the colors that you use for the planets using the background color of your chartwheel.
The Glyph Separation value represents the minimum number of degrees necessary to give space for each individual glyph. Because this graph is drawn as a line and not as a circle (as in a chartwheel) there is less space distributed, so the value has to be larger to maintain distance between the glyphs. Much depends upon the resolution of your screen. Eight degrees is the default.
