ETrack
ETrack stands for Entity Tracking. ETrack is a tool that helps you draw in relationship to other entities by displaying temporary guides and markers to which you can snap. According the DraftSight’s help file, ETrack will “snap to geometrically significant points on drawing entities, for example, end points, intersections, and center points”.
ETrack works in conjunction with ESnap, because of this, ESnap must be enabled for ETrack to function correctly.
ETrack markers are activated by hovering over areas such as end points, intersections, and center points until a small blue plus sign 
appears. Markers can be difficult to acquire, so patience is needed.
In the example below, an ETrack point on the rectangle was activated. The marker, a triangle, tells us that ETrack has found a midpoint. Once the marker is activated, ETrack will display a dotted line. This dotted line will appear whenever the crosshairs is close to 0°, 45°, 90° and so on, of the tracking point.
You can also see that the intersection ESnap marker is displayed inside the gravity box, meaning that if I were to click, I would specify the a point along the ETrack dotted line.
In the next image, I have activated one more ETrack tracking point, this time on the midpoint of the top of the rectangle.
You will also see that the intersection ESnap marker has now moved to the intersection of the two tracking points. Since both of our tracking points are perpendicular to the midpoint, the intersection will be the exact center of the rectangle.
There is no limit as to how many tracking points can be activated at any one time.